JavaScript – How to loop an Array

By mkyong | Updated: March 22, 2019

Viewed: 429

Tags: array javascript loop

In JavaScript, we can use for, forEach or for..of to loop an Array.

1.1 for

	//old-school, classic for loop
	var str = ["a", "b", "c", "d", "e"];
	for(var i =0; i < str.length; i++){
		console.log(str[i]); //a,b,c,d,e
	}

output

a
b
c
d
e

1.2 forEach()

	var num = [1, 2, 3, 4, 5];
	num.forEach(anyFunction)

	function anyFunction(data){
		console.log(data);
	}

output

1
2
3
4
5

1.3 for..of

	var strArray = ["a", "b", "c", "d", "e"];
	for(var s of strArray){
		console.log(s);
	}

output

a
b
c
d
e

References

• ECMAScript 2015 Language Specification
• MDN – Array.forEach()
• JavaScript – Array forEach examples