--- title: Array.prototype.includes() slug: Web/JavaScript/Reference/Global_Objects/Array/includes translation_of: Web/JavaScript/Reference/Global_Objects/Array/includes original_slug: Web/JavaScript/Referencje/Obiekty/Array/includes ---
Metoda includes()
ustala czy dana tablica posiada szukany element, zwracając true
lub false.
var boolean = array.includes(searchElement[, fromIndex])
{{jsxref("Boolean")}}.
searchElement
fromIndex
searchElement
. Ujemna wartość przeszukuje tablicę od końca tablicy. Domyślna wartość wynosi 0.[1, 2, 3].includes(2); // true [1, 2, 3].includes(4); // false [1, 2, 3].includes(3, 3); // false [1, 2, 3].includes(3, -1); // true [1, 2, NaN].includes(NaN); // true
if (!Array.prototype.includes) { Array.prototype.includes = function(searchElement /*, fromIndex*/ ) { 'use strict'; var O = Object(this); var len = parseInt(O.length) || 0; if (len === 0) { return false; } var n = parseInt(arguments[1]) || 0; var k; if (n >= 0) { k = n; } else { k = len + n; if (k < 0) {k = 0;} } var currentElement; while (k < len) { currentElement = O[k]; if (searchElement === currentElement || (searchElement !== searchElement && currentElement !== currentElement)) { // NaN !== NaN return true; } k++; } return false; }; }
Specyfikacja | Status | Komentarz |
---|---|---|
{{SpecName('ES7', '#sec-array.prototype.includes', 'Array.prototype.includes')}} | {{Spec2('ES7')}} | Definicja początkowa. |
{{SpecName('ESDraft', '#sec-array.prototype.includes', 'Array.prototype.includes')}} | {{Spec2('ESDraft')}} |
|
{{Compat("javascript.builtins.Array.includes")}}