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  1. @ajeetkumarrauniyar ajeetkumarrauniyar revised this gist Feb 26, 2024. 2 changed files with 367 additions and 230 deletions.
    367 changes: 367 additions & 0 deletions Array CheatSheet.md
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    # Array Methods Cheat Sheet

    ## 1. push()
    - **Definition:** Adds one or more elements to the end of an array and returns the new length of the array.
    - **Syntax:** `array.push(element1[, ...[, elementN]])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    arr.push(4, 5);
    console.log(arr); // Output: [1, 2, 3, 4, 5]
    ```

    ## 2. pop()
    - **Definition:** Removes the last element from an array and returns that element.
    - **Syntax:** `array.pop()`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    let removedElement = arr.pop();
    console.log(removedElement); // Output: 3
    console.log(arr); // Output: [1, 2]
    ```

    ## 3. shift()
    - **Definition:** Removes the first element from an array and returns that element.
    - **Syntax:** `array.shift()`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    let shiftedElement = arr.shift();
    console.log(shiftedElement); // Output: 1
    console.log(arr); // Output: [2, 3]
    ```

    ## 4. unshift()
    - **Definition:** Adds one or more elements to the beginning of an array and returns the new length of the array.
    - **Syntax:** `array.unshift(element1[, ...[, elementN]])`
    - **Example:**
    ```javascript
    let arr = [2, 3];
    arr.unshift(0, 1);
    console.log(arr); // Output: [0, 1, 2, 3]
    ```

    ## 5. concat()
    - **Definition:** Returns a new array comprised of the array on which it is called joined with the array(s) and/or value(s) provided as arguments.
    - **Syntax:** `array.concat(value1[, value2[, ...[, valueN]]])`
    - **Example:**
    ```javascript
    let arr1 = [1, 2];
    let arr2 = [3, 4];
    let newArr = arr1.concat(arr2);
    console.log(newArr); // Output: [1, 2, 3, 4]
    ```

    ## 6. slice()
    - **Definition:** Returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included) where begin and end represent the index of items in that array.
    - **Syntax:** `array.slice(begin[, end])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4, 5];
    let newArr = arr.slice(1, 3);
    console.log(newArr); // Output: [2, 3]
    ```

    ## 7. splice()
    - **Definition:** Changes the contents of an array by removing or replacing existing elements and/or adding new elements in place.
    - **Syntax:** `array.splice(start[, deleteCount[, item1[, item2[, ...]]]])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4, 5];
    arr.splice(1, 2, 'a', 'b');
    console.log(arr); // Output: [1, 'a', 'b', 4, 5]
    ```

    ## 8. forEach()
    - **Definition:** Executes a provided function once for each array element.
    - **Syntax:** `array.forEach(callback(currentValue [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    arr.forEach(element => console.log(element * 2));
    // Output:
    // 2
    // 4
    // 6
    ```

    ## 9. map()
    - **Definition:** Creates a new array populated with the results of calling a provided function on every element in the calling array.
    - **Syntax:** `array.map(callback(currentValue [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    let newArr = arr.map(element => element * 2);
    console.log(newArr); // Output: [2, 4, 6]
    ```

    ## 10. filter()
    - **Definition:** Creates a new array with all elements that pass the test implemented by the provided function.
    - **Syntax:** `array.filter(callback(element [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4, 5];
    let newArr = arr.filter(element => element % 2 === 0);
    console.log(newArr); // Output: [2, 4]
    ```

    ## 11. find()
    - **Definition:** Returns the value of the first element in the array that satisfies the provided testing function. Otherwise, it returns `undefined`.
    - **Syntax:** `array.find(callback(element [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [5, 12, 8, 130, 44];
    let found = arr.find(element => element > 10);
    console.log(found); // Output: 12
    ```

    ## 12. findIndex()
    - **Definition:** Returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1.
    - **Syntax:** `array.findIndex(callback(element [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [5, 12, 8, 130, 44];
    let foundIndex = arr.findIndex(element => element > 10);
    console.log(foundIndex); // Output: 1
    ```

    ## 13. every()
    - **Definition:** Tests whether all elements in the array pass the test implemented by the provided function. It returns a Boolean value.
    - **Syntax:** `array.every(callback(element [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [30, 40, 50, 60];
    let allOver20 = arr.every(element => element > 20);
    console.log(allOver20); // Output: true
    ```

    ## 14. some()
    - **Definition:** Tests whether at least one element in the array passes the test implemented by the provided function. It returns a Boolean value.
    - **Syntax:** `array.some(callback(element [, index [, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [10, 20, 30, 40, 50];
    let someOver30 = arr.some(element => element > 30);
    console.log(someOver30); // Output: true
    ```

    ## 15. includes()
    - **Definition:** Determines whether an array includes a certain value among its entries, returning true or false as appropriate.
    - **Syntax:** `array.includes(valueToFind [, fromIndex])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    let includesTwo = arr.includes(2);
    console.log(includesTwo); // Output: true
    ```

    ## 16. indexOf()
    - **Definition:** Returns the first index at which a given element can be found in the array, or -1 if it is not present.
    - **Syntax:** `array.indexOf(searchElement [, fromIndex])`
    - **Example:**
    ```javascript
    let arr = [2, 9, 9];
    let index = arr.indexOf(9);
    console.log(index); // Output: 1
    ```
    ## 17. reduce()
    - **Definition:** Executes a reducer function on each element of the array, resulting in a single output value.
    - **Syntax:** `array.reduce(callback(accumulator, currentValue[, index, array])[, initialValue])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4];
    let sum = arr.reduce((acc, curr) => acc + curr);
    console.log(sum); // Output: 10
    ```

    ## 18. reduceRight()
    - **Definition:** Similar to `reduce()`, but applies the function from right to left instead of left to right.
    - **Syntax:** `array.reduceRight(callback(accumulator, currentValue[, index, array])[, initialValue])`
    - **Example:**
    ```javascript
    let arr = ['a', 'b', 'c', 'd'];
    let concat = arr.reduceRight((acc, curr) => acc + curr);
    console.log(concat); // Output: 'dcba'
    ```

    ## 19. join()
    - **Definition:** Creates and returns a new string by concatenating all of the elements in an array, separated by commas or a specified separator string.
    - **Syntax:** `array.join(separator)`
    - **Example:**
    ```javascript
    let arr = ['Hello', 'World'];
    let str = arr.join(' ');
    console.log(str); // Output: 'Hello World'
    ```

    ## 20. reverse()
    - **Definition:** Reverses the elements of an array in place. The first array element becomes the last, and the last array element becomes the first.
    - **Syntax:** `array.reverse()`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    arr.reverse();
    console.log(arr); // Output: [3, 2, 1]
    ```

    ## 21. sort()
    - **Definition:** Sorts the elements of an array in place and returns the sorted array.
    - **Syntax:** `array.sort([compareFunction])`
    - **Example:**
    ```javascript
    let arr = [5, 2, 1, 4, 3];
    arr.sort((a, b) => a - b);
    console.log(arr); // Output: [1, 2, 3, 4, 5]
    ```

    ## 22. toString()
    - **Definition:** Returns a string representing the specified array and its elements.
    - **Syntax:** `array.toString()`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    let str = arr.toString();
    console.log(str); // Output: '1,2,3'
    ```
    ## 23. flat()
    - **Definition:** Creates a new array with all sub-array elements concatenated into it recursively up to the specified depth.
    - **Syntax:** `array.flat([depth])`
    - **Example:**
    ```javascript
    let arr = [1, 2, [3, 4, [5, 6]]];
    let flatArr = arr.flat(2);
    console.log(flatArr); // Output: [1, 2, 3, 4, 5, 6]
    ```

    ## 24. flatMap()
    - **Definition:** First maps each element using a mapping function, then flattens the result into a new array.
    - **Syntax:** `array.flatMap(callback(currentValue[, index[, array]])[, thisArg])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    let mappedArr = arr.flatMap(x => [x * 2]);
    console.log(mappedArr); // Output: [2, 4, 6]
    ```

    ## 25. length
    - **Definition:** Returns the number of elements in the array.
    - **Syntax:** `array.length`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4, 5];
    console.log(arr.length); // Output: 5
    ```

    ## 26. isArray()
    - **Definition:** Determines whether the passed value is an Array.
    - **Syntax:** `Array.isArray(value)`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3];
    console.log(Array.isArray(arr)); // Output: true
    ```

    ## 27. fill()
    - **Definition:** Fills all the elements of an array from a start index to an end index with a static value.
    - **Syntax:** `array.fill(value[, start[, end]])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4, 5];
    arr.fill(0, 2, 4);
    console.log(arr); // Output: [1, 2, 0, 0, 5]
    ```

    ## 28. keys()
    - **Definition:** Returns a new Array Iterator object that contains the keys for each index in the array.
    - **Syntax:** `array.keys()`
    - **Example:**
    ```javascript
    let arr = ['a', 'b', 'c'];
    let iterator = arr.keys();
    for (let key of iterator) {
    console.log(key); // Output: 0, 1, 2
    }
    ```

    ## 29. values()
    - **Definition:** Returns a new Array Iterator object that contains the values for each index in the array.
    - **Syntax:** `array.values()`
    - **Example:**
    ```javascript
    let arr = ['a', 'b', 'c'];
    let iterator = arr.values();
    for (let value of iterator) {
    console.log(value); // Output: 'a', 'b', 'c'
    }
    ```

    ## 30. entries()
    - **Definition:** Returns a new Array Iterator object that contains the key/value pairs for each index in the array.
    - **Syntax:** `array.entries()`
    - **Example:**
    ```javascript
    let arr = ['a', 'b', 'c'];
    let iterator = arr.entries();
    for (let entry of iterator) {
    console.log(entry); // Output: [0, 'a'], [1, 'b'], [2, 'c']
    }
    ```

    ## 31. from()
    - **Definition:** Creates a new, shallow-copied Array instance from an array-like or iterable object.
    - **Syntax:** `Array.from(arrayLike[, mapFn[, thisArg]])`
    - **Example:**
    ```javascript
    let arrLike = 'hello';
    let newArr = Array.from(arrLike);
    console.log(newArr); // Output: ['h', 'e', 'l', 'l', 'o']
    ```

    ## 32. copyWithin()
    - **Definition:** Copies a sequence of array elements within the array.
    - **Syntax:** `array.copyWithin(target, start[, end])`
    - **Example:**
    ```javascript
    let arr = [1, 2, 3, 4, 5];
    arr.copyWithin(0, 3);
    console.log(arr); // Output: [4, 5, 3, 4, 5]
    ```

    ## 33. at()
    - **Definition:** Returns the element at the specified index in the array.
    - **Syntax:** `array.at(index)`
    - **Example:**
    ```javascript
    let arr = [10, 20, 30, 40, 50];
    console.log(arr.at(2)); // Output: 30
    ```

    ## 34. lastIndexOf()
    - **Definition:** Returns the last index at which a given element can be found in the array, or -1 if it is not present. Searches the array from a specified index if provided.
    - **Syntax:** `array.lastIndexOf(searchElement[, fromIndex])`
    - **Example:**
    ```javascript
    let arr = [2, 9, 9, 4, 6];
    let index = arr.lastIndexOf(9);
    console.log(index); // Output: 2
    ```

    ## 35. toLocaleString()
    - **Definition:** Returns a string representing the elements of the array. The elements are converted to strings using their toLocaleString methods.
    - **Syntax:** `array.toLocaleString([locales[, options]])`
    - **Example:**
    ```javascript
    let arr = [1, new Date(), 'a', { key: 'value' }];
    let str = arr.toLocaleString();
    console.log(str); // Output: '1,Sat Feb 27 2024 19:58:46 GMT+0000 (Coordinated Universal Time),a,[object Object]'
    ```

    ## 36. of()
    - **Definition:** Creates a new Array instance with a variable number of arguments.
    - **Syntax:** `Array.of(element0[, element1[, ...[, elementN]]])`
    - **Example:**
    ```javascript
    let arr = Array.of(1, 2, 3, 4, 5);
    console.log(arr); // Output: [1, 2, 3, 4, 5]
    ```
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    Array Methods Cheat Sheet

    1. push()
    - Definition: Adds one or more elements to the end of an array and returns the new length of the array.
    - Syntax: array.push(element1[, ...[, elementN]])
    - Example:
    let arr = [1, 2, 3];
    arr.push(4, 5);
    console.log(arr); // Output: [1, 2, 3, 4, 5]

    2. pop()
    - Definition: Removes the last element from an array and returns that element.
    - Syntax: array.pop()
    - Example:
    let arr = [1, 2, 3];
    let removedElement = arr.pop();
    console.log(removedElement); // Output: 3

    3. shift()
    - Definition: Removes the first element from an array and returns that element.
    - Syntax: array.shift()
    - Example:
    let arr = [1, 2, 3];
    let shiftedElement = arr.shift();
    console.log(shiftedElement); // Output: 1

    4. unshift()
    - Definition: Adds one or more elements to the beginning of an array and returns the new length of the array.
    - Syntax: array.unshift(element1[, ...[, elementN]])
    - Example:
    let arr = [2, 3];
    arr.unshift(0, 1);
    console.log(arr); // Output: [0, 1, 2, 3]

    5. concat()
    - Definition: Returns a new array comprised of the array on which it is called joined with the array(s) and/or value(s) provided as arguments.
    - Syntax: array.concat(value1[, value2[, ...[, valueN]]])
    - Example:
    let arr1 = [1, 2];
    let arr2 = [3, 4];
    let newArr = arr1.concat(arr2);
    console.log(newArr); // Output: [1, 2, 3, 4]

    6. slice()
    - Definition: Returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included) where begin and end represent the index of items in that array.
    - Syntax: array.slice(begin[, end])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    let newArr = arr.slice(1, 3);
    console.log(newArr); // Output: [2, 3]

    7. splice()
    - Definition: Changes the contents of an array by removing or replacing existing elements and/or adding new elements in place.
    - Syntax: array.splice(start[, deleteCount[, item1[, item2[, ...]]]])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    arr.splice(1, 2, 'a', 'b');
    console.log(arr); // Output: [1, 'a', 'b', 4, 5]

    8. forEach()
    - Definition: Executes a provided function once for each array element.
    - Syntax: array.forEach(callback(currentValue [, index [, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3];
    arr.forEach(element => console.log(element * 2));
    // Output:
    // 2
    // 4
    // 6

    9. map()
    - Definition: Creates a new array populated with the results of calling a provided function on every element in the calling array.
    - Syntax: array.map(callback(currentValue [, index [, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3];
    let newArr = arr.map(element => element * 2);
    console.log(newArr); // Output: [2, 4, 6]

    10. filter()
    - Definition: Creates a new array with all elements that pass the test implemented by the provided function.
    - Syntax: array.filter(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    let newArr = arr.filter(element => element % 2 === 0);
    console.log(newArr); // Output: [2, 4]

    11. find()
    - Definition: Returns the value of the first element in the array that satisfies the provided testing function. Otherwise, it returns `undefined`.
    - Syntax: array.find(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [5, 12, 8, 130, 44];
    let found = arr.find(element => element > 10);
    console.log(found); // Output: 12

    12. findIndex()
    - Definition: Returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1.
    - Syntax: array.findIndex(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [5, 12, 8, 130, 44];
    let foundIndex = arr.findIndex(element => element > 10);
    console.log(foundIndex); // Output: 1

    13. every()
    - Definition: Tests whether all elements in the array pass the test implemented by the provided function. It returns a Boolean value.
    - Syntax: array.every(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [30, 40, 50, 60];
    let allOver20 = arr.every(element => element > 20);
    console.log(allOver20); // Output: true

    14. some()
    - Definition: Tests whether at least one element in the array passes the test implemented by the provided function. It returns a Boolean value.
    - Syntax: array.some(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [10, 20, 30, 40, 50];
    let someOver30 = arr.some(element => element > 30);
    console.log(someOver30); // Output: true

    15. includes()
    - Definition: Determines whether an array includes a certain value among its entries, returning true or false as appropriate.
    - Syntax: array.includes(valueToFind [, fromIndex])
    - Example:
    let arr = [1, 2, 3];
    let includesTwo = arr.includes(2);
    console.log(includesTwo); // Output: true

    16. indexOf()
    - Definition: Returns the first index at which a given element can be found in the array, or -1 if it is not present.
    - Syntax: array.indexOf(searchElement [, fromIndex])
    - Example:
    let arr = [2, 9, 9];
    let index = arr.indexOf(9);
    console.log(index); // Output: 1

    17. reduce()
    - Definition: Executes a reducer function on each element of the array, resulting in a single output value.
    - Syntax: array.reduce(callback(accumulator, currentValue[, index, array])[, initialValue])
    - Example:
    let arr = [1, 2, 3, 4];
    let sum = arr.reduce((acc, curr) => acc + curr);
    console.log(sum); // Output: 10

    18. reduceRight()
    - Definition: Similar to reduce(), but applies the function from right to left instead of left to right.
    - Syntax: array.reduceRight(callback(accumulator, currentValue[, index, array])[, initialValue])
    - Example:
    let arr = ['a', 'b', 'c', 'd'];
    let concat = arr.reduceRight((acc, curr) => acc + curr);
    console.log(concat); // Output: 'dcba'

    19. join()
    - Definition: Creates and returns a new string by concatenating all of the elements in an array, separated by commas or a specified separator string.
    - Syntax: array.join(separator)
    - Example:
    let arr = ['Hello', 'World'];
    let str = arr.join(' ');
    console.log(str); // Output: 'Hello World'

    20. reverse()
    - Definition: Reverses the elements of an array in place. The first array element becomes the last, and the last array element becomes the first.
    - Syntax: array.reverse()
    - Example:
    let arr = [1, 2, 3];
    arr.reverse();
    console.log(arr); // Output: [3, 2, 1]

    21. sort()
    - Definition: Sorts the elements of an array in place and returns the sorted array.
    - Syntax: array.sort([compareFunction])
    - Example:`
    let arr = [5, 2, 1, 4, 3];
    arr.sort((a, b) => a - b);
    console.log(arr); // Output: [1, 2, 3, 4, 5]

    22. toString()
    - Definition: Returns a string representing the specified array and its elements.
    - Syntax: array.toString()
    - Example:
    let arr = [1, 2, 3];
    let str = arr.toString();
    console.log(str); // Output: '1,2,3'

    23. flat()
    - Definition: Creates a new array with all sub-array elements concatenated into it recursively up to the specified depth.
    - Syntax: array.flat([depth])
    - Example:
    let arr = [1, 2, [3, 4, [5, 6]]];
    let flatArr = arr.flat(2);
    console.log(flatArr); // Output: [1, 2, 3, 4, 5, 6]

    24. flatMap()
    - Definition: First maps each element using a mapping function, then flattens the result into a new array.
    - Syntax: array.flatMap(callback(currentValue[, index[, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3];
    let mappedArr = arr.flatMap(x => [x * 2]);
    console.log(mappedArr); // Output: [2, 4, 6]

    25. slice()
    - Definition: Returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included) where begin and end represent the index of items in that array.
    - Syntax: array.slice([start], [end])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    let slicedArr = arr.slice(1, 4);
    console.log(slicedArr); // Output: [2, 3, 4]

    26. isArray()
    - Definition: Determines whether the passed value is an Array.
    - Syntax: Array.isArray(value)
    - Example:
    let arr = [1, 2, 3];
    console.log(Array.isArray(arr)); // Output: true

    27. fill()
    - Definition: Fills all the elements of an array from a start index to an end index with a static value.
    - Syntax: array.fill(value[, start[, end]])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    arr.fill(0, 2, 4);
    console.log(arr); // Output: [1, 2, 0, 0, 5]

    28. keys()
    - Definition: Returns a new Array Iterator object that contains the keys for each index in the array.
    - Syntax: array.keys()
    - Example:
    let arr = ['a', 'b', 'c'];
    let iterator = arr.keys();
    for (let key of iterator) {
    console.log(key); // Output: 0, 1, 2
    }
  2. @ajeetkumarrauniyar ajeetkumarrauniyar created this gist Feb 26, 2024.
    230 changes: 230 additions & 0 deletions gistfile1.txt
    View file
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    @@ -0,0 +1,230 @@
    Array Methods Cheat Sheet

    1. push()
    - Definition: Adds one or more elements to the end of an array and returns the new length of the array.
    - Syntax: array.push(element1[, ...[, elementN]])
    - Example:
    let arr = [1, 2, 3];
    arr.push(4, 5);
    console.log(arr); // Output: [1, 2, 3, 4, 5]

    2. pop()
    - Definition: Removes the last element from an array and returns that element.
    - Syntax: array.pop()
    - Example:
    let arr = [1, 2, 3];
    let removedElement = arr.pop();
    console.log(removedElement); // Output: 3

    3. shift()
    - Definition: Removes the first element from an array and returns that element.
    - Syntax: array.shift()
    - Example:
    let arr = [1, 2, 3];
    let shiftedElement = arr.shift();
    console.log(shiftedElement); // Output: 1

    4. unshift()
    - Definition: Adds one or more elements to the beginning of an array and returns the new length of the array.
    - Syntax: array.unshift(element1[, ...[, elementN]])
    - Example:
    let arr = [2, 3];
    arr.unshift(0, 1);
    console.log(arr); // Output: [0, 1, 2, 3]

    5. concat()
    - Definition: Returns a new array comprised of the array on which it is called joined with the array(s) and/or value(s) provided as arguments.
    - Syntax: array.concat(value1[, value2[, ...[, valueN]]])
    - Example:
    let arr1 = [1, 2];
    let arr2 = [3, 4];
    let newArr = arr1.concat(arr2);
    console.log(newArr); // Output: [1, 2, 3, 4]

    6. slice()
    - Definition: Returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included) where begin and end represent the index of items in that array.
    - Syntax: array.slice(begin[, end])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    let newArr = arr.slice(1, 3);
    console.log(newArr); // Output: [2, 3]

    7. splice()
    - Definition: Changes the contents of an array by removing or replacing existing elements and/or adding new elements in place.
    - Syntax: array.splice(start[, deleteCount[, item1[, item2[, ...]]]])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    arr.splice(1, 2, 'a', 'b');
    console.log(arr); // Output: [1, 'a', 'b', 4, 5]

    8. forEach()
    - Definition: Executes a provided function once for each array element.
    - Syntax: array.forEach(callback(currentValue [, index [, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3];
    arr.forEach(element => console.log(element * 2));
    // Output:
    // 2
    // 4
    // 6

    9. map()
    - Definition: Creates a new array populated with the results of calling a provided function on every element in the calling array.
    - Syntax: array.map(callback(currentValue [, index [, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3];
    let newArr = arr.map(element => element * 2);
    console.log(newArr); // Output: [2, 4, 6]

    10. filter()
    - Definition: Creates a new array with all elements that pass the test implemented by the provided function.
    - Syntax: array.filter(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    let newArr = arr.filter(element => element % 2 === 0);
    console.log(newArr); // Output: [2, 4]

    11. find()
    - Definition: Returns the value of the first element in the array that satisfies the provided testing function. Otherwise, it returns `undefined`.
    - Syntax: array.find(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [5, 12, 8, 130, 44];
    let found = arr.find(element => element > 10);
    console.log(found); // Output: 12

    12. findIndex()
    - Definition: Returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1.
    - Syntax: array.findIndex(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [5, 12, 8, 130, 44];
    let foundIndex = arr.findIndex(element => element > 10);
    console.log(foundIndex); // Output: 1

    13. every()
    - Definition: Tests whether all elements in the array pass the test implemented by the provided function. It returns a Boolean value.
    - Syntax: array.every(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [30, 40, 50, 60];
    let allOver20 = arr.every(element => element > 20);
    console.log(allOver20); // Output: true

    14. some()
    - Definition: Tests whether at least one element in the array passes the test implemented by the provided function. It returns a Boolean value.
    - Syntax: array.some(callback(element [, index [, array]])[, thisArg])
    - Example:
    let arr = [10, 20, 30, 40, 50];
    let someOver30 = arr.some(element => element > 30);
    console.log(someOver30); // Output: true

    15. includes()
    - Definition: Determines whether an array includes a certain value among its entries, returning true or false as appropriate.
    - Syntax: array.includes(valueToFind [, fromIndex])
    - Example:
    let arr = [1, 2, 3];
    let includesTwo = arr.includes(2);
    console.log(includesTwo); // Output: true

    16. indexOf()
    - Definition: Returns the first index at which a given element can be found in the array, or -1 if it is not present.
    - Syntax: array.indexOf(searchElement [, fromIndex])
    - Example:
    let arr = [2, 9, 9];
    let index = arr.indexOf(9);
    console.log(index); // Output: 1

    17. reduce()
    - Definition: Executes a reducer function on each element of the array, resulting in a single output value.
    - Syntax: array.reduce(callback(accumulator, currentValue[, index, array])[, initialValue])
    - Example:
    let arr = [1, 2, 3, 4];
    let sum = arr.reduce((acc, curr) => acc + curr);
    console.log(sum); // Output: 10

    18. reduceRight()
    - Definition: Similar to reduce(), but applies the function from right to left instead of left to right.
    - Syntax: array.reduceRight(callback(accumulator, currentValue[, index, array])[, initialValue])
    - Example:
    let arr = ['a', 'b', 'c', 'd'];
    let concat = arr.reduceRight((acc, curr) => acc + curr);
    console.log(concat); // Output: 'dcba'

    19. join()
    - Definition: Creates and returns a new string by concatenating all of the elements in an array, separated by commas or a specified separator string.
    - Syntax: array.join(separator)
    - Example:
    let arr = ['Hello', 'World'];
    let str = arr.join(' ');
    console.log(str); // Output: 'Hello World'

    20. reverse()
    - Definition: Reverses the elements of an array in place. The first array element becomes the last, and the last array element becomes the first.
    - Syntax: array.reverse()
    - Example:
    let arr = [1, 2, 3];
    arr.reverse();
    console.log(arr); // Output: [3, 2, 1]

    21. sort()
    - Definition: Sorts the elements of an array in place and returns the sorted array.
    - Syntax: array.sort([compareFunction])
    - Example:`
    let arr = [5, 2, 1, 4, 3];
    arr.sort((a, b) => a - b);
    console.log(arr); // Output: [1, 2, 3, 4, 5]

    22. toString()
    - Definition: Returns a string representing the specified array and its elements.
    - Syntax: array.toString()
    - Example:
    let arr = [1, 2, 3];
    let str = arr.toString();
    console.log(str); // Output: '1,2,3'

    23. flat()
    - Definition: Creates a new array with all sub-array elements concatenated into it recursively up to the specified depth.
    - Syntax: array.flat([depth])
    - Example:
    let arr = [1, 2, [3, 4, [5, 6]]];
    let flatArr = arr.flat(2);
    console.log(flatArr); // Output: [1, 2, 3, 4, 5, 6]

    24. flatMap()
    - Definition: First maps each element using a mapping function, then flattens the result into a new array.
    - Syntax: array.flatMap(callback(currentValue[, index[, array]])[, thisArg])
    - Example:
    let arr = [1, 2, 3];
    let mappedArr = arr.flatMap(x => [x * 2]);
    console.log(mappedArr); // Output: [2, 4, 6]

    25. slice()
    - Definition: Returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included) where begin and end represent the index of items in that array.
    - Syntax: array.slice([start], [end])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    let slicedArr = arr.slice(1, 4);
    console.log(slicedArr); // Output: [2, 3, 4]

    26. isArray()
    - Definition: Determines whether the passed value is an Array.
    - Syntax: Array.isArray(value)
    - Example:
    let arr = [1, 2, 3];
    console.log(Array.isArray(arr)); // Output: true

    27. fill()
    - Definition: Fills all the elements of an array from a start index to an end index with a static value.
    - Syntax: array.fill(value[, start[, end]])
    - Example:
    let arr = [1, 2, 3, 4, 5];
    arr.fill(0, 2, 4);
    console.log(arr); // Output: [1, 2, 0, 0, 5]

    28. keys()
    - Definition: Returns a new Array Iterator object that contains the keys for each index in the array.
    - Syntax: array.keys()
    - Example:
    let arr = ['a', 'b', 'c'];
    let iterator = arr.keys();
    for (let key of iterator) {
    console.log(key); // Output: 0, 1, 2
    }