1const posts = [
2 { id: 1, title: "Sample Title 1", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
3 { id: 2, title: "Sample Title 2", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
4 { id: 3, title: "Sample Title 3", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
5];
6// ES2016+
7// Create new array of post IDs. I.e. [1,2,3]
8const postIds = posts.map((post) => post.id);
9// Create new array of post objects. I.e. [{ id: 1, title: "Sample Title 1" }]
10const postSummaries = posts.map((post) => ({ id: post.id, title: post.title }));
11
12// ES2015
13// Create new array of post IDs. I.e. [1,2,3]
14var postIds = posts.map(function (post) { return post.id; });
15// Create new array of post objects. I.e. [{ id: 1, title: "Sample Title 1" }]
16var postSummaries = posts.map(function (post) { return { id: post.id, title: post.title }; });
1function listFruits() {
2 let fruits = ["apple", "cherry", "pear"]
3
4 fruits.map((fruit, index) => {
5 console.log(index, fruit)
6 })
7}
8
9listFruits()
10
11// https://jsfiddle.net/tmoreland/16qfpkgb/3/
1const array1 = [1, 4, 9, 16];
2
3// pass a function to map
4const map1 = array1.map(x => x * 2);
5
6console.log(map1);
7// expected output: Array [2, 8, 18, 32]
1const array1 = [1, 4, 9, 16];
2
3// pass a function to map
4const map1 = array1.map(x => x * 2);
5
6console.log(map1);
7// expected output: Array [2, 8, 18, 32]
8
1const sweetArray = [2, 3, 4, 5, 35]
2const sweeterArray = sweetArray.map(sweetItem => {
3 return sweetItem * 2
4})
5
6console.log(sweeterArray)
1const myArray = ['Sam', 'Alice', 'Nick', 'Matt'];
2
3// Appends text to each element of the array
4const newArray = myArray.map(name => {
5 return 'My name is ' + name;
6});
7console.log(newArray); // ['My name is Sam', 'My Name is Alice', ...]
8
9// Appends the index of each element with it's value
10const anotherArray = myArray.map((value, index) => index + ": " + value);
11console.log(anotherArray); // ['0: Sam', '1: Alice', '2: Nick', ...]
12
13// Starting array is unchanged
14console.log(myArray); // ['Sam', 'Alice', 'Nick', 'Matt']