javascript for in array code example

Example 1: 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 2: javascript loop object

let obj = {
  key1: "value1",
  key2: "value2",
  key3: "value3"
}

Object.keys(obj).forEach(key => {
    console.log(key, obj[key]);
});
// key1 value1
// key2 value2
// key3 value3

// using for in - same output as above
for (let key in obj) {
  let value = obj[key];
  console.log(key, value);
}

Example 3: loop array javascript

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

Example 4: js loop through object

const obj = { a: 1, b: 2 };

Object.keys(obj).forEach(key => {
	console.log("key: ", key);
  	console.log("Value: ", obj[key]);
} );

Example 5: js loop array

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

Example 6: javascript loop through array

var myStringArray = ["hey","World"];
var arrayLength = myStringArray.length;
for (var i = 0; i < arrayLength; i++) {
    console.log(myStringArray[i]);
    //Do something
}