array loops 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: 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: loop array javascript

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

Example 4: loop an array in javascript

let array = ["loop", "this", "array"]; // input array variable
for (let i = 0; i < array.length; i++) { // iteration over input
	console.log(array[i]); // logs the elements from the current input
}

Example 5: javascript loop and array

var array = ["hello","world"];
array.forEach(item=>{
	console.log(item);
});