JSFiddle - React, Tailwind, and code Playground

JavaScript

(function(){
     function checkVarType(variable) {
		var type = typeof variable;
			switch (type) {
				case "number": 
					return "number";
				case "string":
					return "string";
				case "undefined":
					return "undefined";
				case "object":
					var objectType = Object.prototype.toString.call(variable);
					switch (objectType) {
						case "[object Null]":
							return "null";
						case "[object Array]":
							return "Array";
						case "[object Object]":
							return "Object";
						default:
							if (variable.length) {
									return "array-like";
								}
							}
					}
                    break;
				case "boolean": 
					return "boolean";
				case "function":
					return "function";
			}
	};
	console.log(checkVarType(null));
	console.log(checkVarType([1,2]));
})();