access object in loop javascript code example

Example 1: object loop in javascript

const object = { a: 1, b: 2, c: 3 };

for (const property in object) {
  console.log(`${property}: ${object[property]}`);
}

Example 2: javascript loop through object

Object.entries(obj).forEach(
    ([key, value]) => console.log(key, value)
);

// Loop using forEach
arr.forEach((item, index) => {
    // TODO
})

// Loop using for...of
for (const item of arr) {
    await something()
}

// Clone new array (not changing the old one)
const arr = [1,2,3]
const newArray = arr.map(item => item * 2)
console.log(newArray)

// Filter array by condition
const arr = [1,2,3,1]
const newArray = arr.filter(item => {
    if (item === 1) { return item }
})
console.log(newArray)

// Join array
const arr1 = [1,2,3]
const arr2 = [4,5,6]
const arr3 = [...arr1, ...arr2]
console.log(arr3)

// Get a property of object
const { email, address } = user
console.log(email, address)

// Copy object/array
const obj = { name: 'my name' }
const clone = { ...obj }
console.log(obj === clone)

Example 3: javascript loop through object

for (var property in object) {
  if (object.hasOwnProperty(property)) {
    // Do things here
  }
}

Example 4: how to iterate through a js object

let object = {
  x: 10,
  y: 10,
  z: 10
};
let keys = Object.keys(object);
// now 3 different ways:
  // method 1:
  key.forEach(function(key){
      let attribute = object[key];
      // do stuff
    }
  );

  //method 2:
  for(let key of keys){
    let attribute = object[key];
    // do stuff
  }

  //method 3:
  for(let i = 0; i < keys.length; i++){
    let key = keys[i];
    let attribute = object[key];
    // do stuff
  }