javascript loop thru 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: javascript loop through array

const numbers = [1, 2, 3, 4]
numbers.forEach(number => {
	console.log(number);
}

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

Example 3: loop through javascript array

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

Example 4: javascript loop through array

const myArray = ["foo","bar"];

// New version

myArray.map(item => console.log(item));

//or

myArray.forEach(item => console.log(x));

//Older version

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