snakeneedy · May 21, 2020 05:22 · May 21, 2020
diff --git a/typeUtil.js b/typeUtil.js
@@ -0,0 +1,36 @@
+const getTypeName = (o) => {
+  if (o === undefined) return 'undefined';
+  if (o === null) return 'null';
+  return o.constructor.name;
+};
+
+const isUndefined = (o) => (o === undefined);
+
+const isNull = (o) => (o === null);
+
+const isString = (o) => (getTypeName(o) === 'String');
+
+const isNumber = (o) => (getTypeName(o) === 'Number');
+
+const isInteger = (o) => (Number.isInteger(o));
+
+const isBoolean = (o) => (getTypeName(o) === 'Boolean');
+
+const isArray = (o) => (Array.isArray(o));
+
+const isPureObject = (o) => (getTypeName(o) === 'Object');
+
+const isSymbol = (o) => (getTypeName(o) === 'Symbol');
+
+export default {
+  getTypeName,
+  isUndefined,
+  isNull,
+  isString,
+  isNumber,
+  isInteger,
+  isBoolean,
+  isArray,
+  isPureObject,
+  isSymbol,
+};