DNA · January 17, 2022 16:13 · Jan 17, 2022
diff --git a/cheatsheet.md b/cheatsheet.md
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+# C# Cheat Sheet
+
+# Strings
+
+```csharp
+"Foo" // string
+'F'   // Char
+```
+
+## Interpolations
+
+```csharp
+Console.WriteLine("c:\source\repos\foo");    // c:sourcereposfoo ⚠️
+Console.WriteLine("c:\\source\\repos\\foo"); // c:\source\repos\foo
+Console.WriteLine(@"c:\source\repos\foo");   // c:\source\repos\foo
+
+string name = "foo";
+string path = $"C:\\source\\repos\\{name}";
+Console.WriteLine(path);                       // c:\source\repos\foo
+Console.WriteLine($@"C:\source\repos\{name}"); // c:\source\repos\foo
+```
+
+# Numbers
+
+## Inplicity type conversion
+
+```csharp
+int qty = 7;
+
+Console.WriteLine("Total: " + qty + 7 + " items");
+//                             └─ Convertions before concatenation
+// Total: 77 items
+```
+```csharp
+int qty = 7;
+
+Console.WriteLine("Total: " + (qty + 7) + " items");
+//                            └─ Use parentesis to change the order
+// Total: 14 items
+```
+
+## Operações
+
+```csharp
+int sum        = 7 + 5; // 12
+int difference = 7 - 5; // 2
+int product    = 7 * 5; // 35
+int quotient   = 7 / 5; // 1 ⚠️
+int modulus    = 7 % 5; // 4
+```
+
+### Integer vs Float vs Decimal
+
+```csharp
+int     quotient = 7 / 5;  // 1
+//                 └───┴── Both Integers, result is Integer
+```
+```csharp
+decimal quotient = 7m / 5;    // 1.4
+decimal quotient = 7  / 5.0m; // 1.4
+//                 └────┴── For fractional results,
+//                          pass one value as a Decimal
+```
+```csharp
+decimal quotient = 7.0 / 5;
+//                  └─ This will fail!
+// error CS0266:
+// Cannot implicitly convert type 'double' to 'decimal'.
+// An explicit conversion exists (are you missing a cast?)
+```
+```csharp
+int     first    = 7;
+int     second   = 5;
+decimal quotient = (decimal) first / second;
+//                     └─ When using variables,
+//                        just cast the needed type!
+```
+
+## Operation Order
+
+In math, `PEMDAS` is an acronym remember the order operations are performed:
+
+```
+- Parentheses    ── Whatever is inside performs first)
+- Exponents      ── ⚠️
+- Multiplication ╮
+- Division       ├─ From left to right
+- Addition       │
+- Subtraction    ╯
+```
+
+> ⚠️ There's no exponent operator in C#, use `System.Math.Pow()` instead