loop over 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: iterate through array javascript

const array = ["one", "two", "three"]
array.forEach(function (item, index) {
  console.log(item, index);
});

Example 4: javascript loop through array

const array1 = ['a', 'b', 'c'];

array1.forEach(element => console.log(element));

Example 5: loop over an array

let fruits = ['Apple', 'Banana'];

fruits.forEach(function(item, index, array) {
  console.log(item, index);
});
// Apple 0
// Banana 1

Example 6: use these instead of a for loop javascript

const array = [1,2,3,4,5];const evenNumbers = array.filter(function(elem) {   // expressions that return 'true' are retained   return elem % 2 == 0;});