{… Many ways in JavaScript }

IIFE(Immediately Invoked Function Expression)

An IIFE (Immediately Invoked Function Expression) is a JavaScript function that runs as soon as it is defined.

Here we are going to write IIFE by 12 ways.

	1.
	(function() {
	console.log("I am called");
	})();
	2.
	(function() {
	console.log("I am called");
	}());
	3.
	~function() {
	console.log("I am called");
	}();
	4.
	!function() {
	console.log("I am called");
	}();
	5.
	+function() {
	console.log("I am called");
	}();
	6.
	-function() {
	console.log("I am called");
	}();
	7.
	[function() {
	console.log("I am called");
	}()];
	8.
	const iife = function(){
	console.log("I am called")
	}();
	9.
	true && function(){
	console.log("I am called")
	}();
	10.
	0, function(){
	console.log("I am called")
	}();
	11.
	new function(){
	console.log("I am called")
	}
	12.
	new function(){
	console.log("I am called")
	}();

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Creating Arrays

The JavaScript Array object is a global object that is used in the construction of arrays; which are high-level, list-like objects. For this topic I would like to say thanks to 2ality.com .

Here we are going to create array by 10 ways.

	1. new Array(2)
	2. Array.from({length : 2})
	3. [… new Array(2)]
	4. let arr =[];
	for(var itr=0; itr<2; itr++){
	arr.push(0)
	}
	5. new Array(2).fill(0)
	6. Array.from({length : 2}, () =>({}))
	7. Array.from(new Array(2))
	8. Array.from(new Array(2), ()=> 0)
	9. Array.from(new Array(2), (x,i)=> i);
	10. [… new Array(2).keys()]

view raw Arrays.js hosted with ❤ by GitHub

Define Function

Functions are one of the fundamental building blocks in JavaScript. A function is a JavaScript procedure — a set of statements that performs a task or calculates a value. To use a function, you must define it somewhere in the scope from which you wish to call it.

Here we can write function by 6+ ways.

	1. function add(a,b){
	return a+b
	}
	2. let add = function(a,b){
	return a+b
	}
	3. let add = (a,b) =>{ return a+b }
	4. let add = new Function('a','b', 'return a+b' )
	5. function* add(item) {
	yield item;
	yield item+ 10;
	}
	var gen = add(10);
	6.
	function *add(item) {
	yield item;
	yield item+ 10;
	}
	var gen = add(10);

view raw functions.js hosted with ❤ by GitHub

Covert to Number

The Number JavaScript object is a wrapper object allowing you to work with numerical values. A Number object is created using the Number() constructor. A primitive type object number created using the Number() function.

Here we can convert string to Number by 9 ways.

	var a = "10";
	1. console.log(+a);
	2. console.log(Number(a));
	3. console.log(1*a);
	4. console.log(a-0);
	5. console.log(parseFloat(a));
	6. console.log(parseInt(a));
	7. console.log(Math.floor(a));
	8. console.log(Math.round(a));
	9.console.log(~~a);
	Note :-
	(i) +, Number and * is fast compare to all.
	(ii) Method 6-9 is not applicable when value in decimal. i.e. ("10.11").

view raw numberFomat.js hosted with ❤ by GitHub