What is the equivalent of python any() and all() functions in JavaScript?

The Python documentation gives you pure-python equivalents for both functions; they are trivial to translate to JavaScript:

function any(iterable) {    for (var index = 0; index < iterable.length; index++) {        if (iterable[index]) return true;    }    return false;}

and

function all(iterable) {    for (var index = 0; index < iterable.length; index++) {        if (!iterable[index]) return false;    }    return true;}

Recent browser versions (implementing ECMAScript 5.1, Firefox 1.5+, Chrome, Edge 12+ and IE 9) have native support in the form of Array.some and Array.every; these take a callback that determines if something is 'true' or not:

some_array.some((elem) => !!elem );some_array.every((elem) => !!elem );

The Mozilla documentation I linked to has polyfills included to recreate these two methods in other JS implementations.

You can use lodash.

lodash.every is equivalent to all

lodash.some is equivalent to any

Build-in function some is equivalent to any I suppose.

const array = [1, 2, 3, 4, 5];const even = function(element) {  // checks whether an element is even  return element % 2 === 0;};console.log(array.some(even));// expected output: true

You can read more in the docs