how to map an array code example

Example 1: javascript map array

const myArray = ['Sam', 'Alice', 'Nick', 'Matt'];

// Appends text to each element of the array
const newArray = myArray.map(name => {
	return 'My name is ' + name; 
});
console.log(newArray); // ['My name is Sam', 'My Name is Alice', ...]

// Appends the index of each element with it's value
const anotherArray = myArray.map((value, index) => index + ": " + value);
console.log(anotherArray); // ['0: Sam', '1: Alice', '2: Nick', ...]

// Starting array is unchanged
console.log(myArray); // ['Sam', 'Alice', 'Nick', 'Matt']

Example 2: array map javascript

const array1 = [1, 4, 9, 16];

// pass a function to map
const map1 = array1.map(x => x * 2);

console.log(map1);
// expected output: Array [2, 8, 18, 32]

Example 3: javascript map array

const array1 = [1, 4, 9, 16];

// pass a function to map
const map1 = array1.map(x => x * 2);

console.log(map1);
// expected output: Array [2, 8, 18, 32]

Example 4: map a property from array of objects javascript

var result = objArray.map(function(a) {return a.foo;});

Example 5: array map

let numbers = [1, 4, 9]
let roots = numbers.map(function(num) {
    return Math.sqrt(num)
})
// roots is now     [1, 2, 3]
// numbers is still [1, 4, 9]

Example 6: array map

let A = [{ x:'x', y:'y' }, { x:'x', y:'y' }];

let result = A.map(({y,...rest})=> ({...rest,v:y}));

console.log(result);