filter and map in javascript code example

Example 1: use .map(), .filter() js

var arr = [1, 25, 20, 4];

var sum = arr.map((item) => item * 10).filter((item) => item > 100);
var sum2 = arr.map((item) => item * 10)
console.log("sum2", sum2)
// sum2 : (4) [10, 250, 200, 40]
console.log("sum", sum);
// sum : (2) [250, 200]

Example 2: map and reduce an array in js

const rebels = pilots.filter(pilot => pilot.faction === "Rebels");const empire = pilots.filter(pilot => pilot.faction === "Empire");

Example 3: js map filter reduce

const numbers = [1, 2, 3, 4];
const doubled = numbers.map(item => item * 2);
console.log(doubled); // [2, 4, 6, 8]

Example 4: js map filter reduce

const numbers = [1, 2, 3, 4];
const evens = numbers.filter(item => item % 2 === 0);
console.log(evens); // [2, 4]

Example 5: map&filter

const files = [ 'foo.txt ', '.bar', '   ', 'baz.foo' ];
const filePaths = files
  .map(file => file.trim())
  .filter(Boolean)
  .map(fileName => `~/cool_app/${fileName}`);

// filePaths = [ '~/cool_app/foo.txt', '~/cool_app/.bar', '~/cool_app/baz.foo']

Example 6: javavscript array.filter with array.map

var arr = [1, 25, 20, 4];

var sum = arr.map((item) => item * 10).filter((item) => item > 100);
var sum2 = arr.map((item) => item * 10)
console.log("sum2", sum2)
// sum2 : (4) [10, 250, 200, 40]
console.log("sum", sum);
// sum : (2) [250, 200]