looping through an 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 code to loop through array

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

Example 4: js loop through array

// ES6 for-of statement
for (const color of colors){
    console.log(color);
}

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

// Sequential for loop
for (var i = 0; i < arrayLength; i++) {
    console.log(myStringArray[i]);
    //Do something
}

Example 5: loop through array javascript

/* ES6 */
const cities = ["Chicago", "New York", "Los Angeles"];
cities.map(city => {
	console.log(city)
})

Example 6: javascript loop through array

let my_array = [1, 2, 3, 4, 5];

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

// for and of method
for(let i of my_array) {
	console.log(i)
}

/*
Results:
1 2 3 4 5
1 2 3 4 5
(From both methods)
*/