array map
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']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]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]
function listFruits() {
let fruits = ["apple", "cherry", "pear"]
fruits.map((fruit, index) => {
console.log(index, fruit)
})
}
listFruits()
// https://jsfiddle.net/tmoreland/16qfpkgb/3/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]
let A = [{ x:'x', y:'y' }, { x:'x', y:'y' }];
let result = A.map(({y,...rest})=> ({...rest,v:y}));
console.log(result);