iterate through array js code example

Example 1: javascript loop through array

var data = [1, 2, 3, 4, 5, 6];

// traditional for loop
for(let i=0; i<=data.length; i++) {
  console.log(data[i])  // 1 2 3 4 5 6
}

// using for...of
for(let i of data) {
	console.log(i) // 1 2 3 4 5 6
}

// using for...in
for(let i in data) {
  	console.log(i) // Prints indices for array elements
	console.log(data[i]) // 1 2 3 4 5 6
}

// using forEach
data.forEach((i) => {
  console.log(i) // 1 2 3 4 5 6
})
// NOTE ->  forEach method is about 95% slower than the traditional for loop

// using map
data.map((i) => {
  console.log(i) // 1 2 3 4 5 6
})

Example 2: javascript code to loop through array

var colors = ["red","blue","green"];
for (var i = 0; i < colors.length; i++) {
    console.log(colors[i]);
}

Example 3: javascript iterate array

var txt = "";
var numbers = [45, 4, 9, 16, 25];

numbers.forEach(function(value, index, array) {
  txt = txt + value + "<br>";
});

Example 4: iterate array javascript

array = [ 1, 2, 3, 4, 5, 6 ]; 
for (index = 0; index < array.length; index++) { 
    console.log(array[index]); 
}

Example 5: javascript loop through array

var colors = ["red","blue","green"];
colors.forEach(function(color) {
  console.log(color);
});

Example 6: iterate through array js

let arbitraryArr = [1, 2, 3];
// below I choose let, but var and const can also be used 
for (let arbitraryElementName of arbitraryArr) {
  console.log(arbitraryElementName);
}