looping array in javascript 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: loop through an array javascript
let array = ['Item 1', 'Item 2', 'Item 3'];
// Here's 4 different ways
for (let index = 0; index < array.length; index++) {
console.log(array[index]);
}
for (let index in array) {
console.log(array[index]);
}
for (let value of array) {
console.log(value); // Will log value in array
}
array.forEach((value, index) => {
console.log(index); // Will log each index
console.log(value); // Will log each value
});
Example 3: javascript iterate array
let array = ['Item 1', 'Item 2', 'Item 3'];
// Here's 4 different ways
for (let index = 0; index < array.length; index++) {
console.log(array[index]);
}
for (let index in array) {
console.log(array[index]);
}
for (let value of array) {
console.log(value); // Will log each value
}
array.forEach((value, index) => {
console.log(index); // Will log each index
console.log(value); // Will log each value
});
Example 4: iterate through array javascript
const array = ["one", "two", "three"]
array.forEach(function (item, index) {
console.log(item, index);
});
Example 5: javascript loop through array
var colors = ["red","blue","green"];
colors.forEach(function(color) {
console.log(color);
});
Example 6: js loop array
let colors = ['red', 'green', 'blue'];
for (const color of colors){
console.log(color);
}