iterating through an array 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 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 3: javascript iterate array

var txt = "";
var numbers = [45, 4, 9, 16, 25];

numbers.forEach(function(value, index, array) {
  txt = txt + value + "<br>";
});

Example 4: iterate array javascript

array = [ 1, 2, 3, 4, 5, 6 ]; 
for (index = 0; index < array.length; index++) { 
    console.log(array[index]); 
}

Example 5: how to loop through an array

int[] numbers = {1,2,3,4,5};
for (int i = 0; i < numbers.length; i++) {
	System.out.println(i);
}

Example 6: 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]);
}