loop on array 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 array

let colors = ['red', 'green', 'blue'];
for (const color of colors){
    console.log(color);
}

Example 5: javascript array loop

const friends = [
   `Dale`,
   `Matt`,
   `Morne`,
   `Michael`,
];

for (let i = 0; i < friends.length; i++) {
   console.log(friends[i]);
}

Example 6: javascript loop array

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
    
    for( var i = 0; i < arr.length; i--){ 
    
        if ( arr[i] === 5) { 
    
            arr.splice(i, 1); 
        }
    
    }
    
    //=> [1, 2, 3, 4, 6, 7, 8, 9, 0]