object for each code example

Example 1: foreach object javascript

const students = {
  adam: {age: 20},
  kevin: {age: 22},
};

Object.entries(students).forEach(student => {
  // key: student[0]
  // value: student[1]
  console.log(`Student: ${student[0]} is ${student[1].age} years old`);
});
/* Output:
Student: adam is 20 years old
Student: kevin is 22 years old
*/

Example 2: javascript foreach object keys

var lunch = {
	sandwich: 'ham',
	snack: 'chips',
	drink: 'soda',
	desert: 'cookie',
	guests: 3,
	alcohol: false,
};

Object.keys(lunch).forEach(function (item) {
	console.log(item); // key
	console.log(lunch[item]); // value
});

// returns "sandwich", "ham", "snack", "chips", "drink", "soda", "desert", "cookie", "guests", 3, "alcohol", false

Example 3: 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 4: foreach object javascript

/* Answer to: "foreach object javascript" */

const games = {
  "Fifa": "232",
  "Minecraft": "476"
  "Call of Duty": "182"
};

Object.keys(games).forEach((item, index, array) => {
  let msg = `There is a game called ${item} and it has sold ${games[item]} million copies.`;
  console.log(msg);
});

/*
  The foreach statement can be used in many ways and with object can make
  development a lot easier.
  
  A link for for more information on this can be found below and in the source:
  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
*/

Example 5: foreach object js

const object1 = {
  a: 'somestring',
  b: 42
};
for (let [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}
// expected output:
// "a: somestring"
// "b: 42"
// order is not guaranteed

Example 6: 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)