mirror of
https://github.com/alextselegidis/easyappointments.git
synced 2024-11-24 17:03:27 +03:00
46 lines
1.5 KiB
JavaScript
46 lines
1.5 KiB
JavaScript
// https://tc39.github.io/ecma262/#sec-array.prototype.find
|
|
if (!Array.prototype.find) {
|
|
Object.defineProperty(Array.prototype, 'find', {
|
|
value: function (predicate) {
|
|
// 1. Let O be ? ToObject(this value).
|
|
if (this == null) {
|
|
throw TypeError('"this" is null or not defined');
|
|
}
|
|
|
|
var o = Object(this);
|
|
|
|
// 2. Let len be ? ToLength(? Get(O, "length")).
|
|
var len = o.length >>> 0;
|
|
|
|
// 3. If IsCallable(predicate) is false, throw a TypeError exception.
|
|
if (typeof predicate !== 'function') {
|
|
throw TypeError('predicate must be a function');
|
|
}
|
|
|
|
// 4. If thisArg was supplied, let T be thisArg; else let T be undefined.
|
|
var thisArg = arguments[1];
|
|
|
|
// 5. Let k be 0.
|
|
var k = 0;
|
|
|
|
// 6. Repeat, while k < len
|
|
while (k < len) {
|
|
// a. Let Pk be ! ToString(k).
|
|
// b. Let kValue be ? Get(O, Pk).
|
|
// c. Let testResult be ToBoolean(? Call(predicate, T, « kValue, k, O »)).
|
|
// d. If testResult is true, return kValue.
|
|
var kValue = o[k];
|
|
if (predicate.call(thisArg, kValue, k, o)) {
|
|
return kValue;
|
|
}
|
|
// e. Increase k by 1.
|
|
k++;
|
|
}
|
|
|
|
// 7. Return undefined.
|
|
return undefined;
|
|
},
|
|
configurable: true,
|
|
writable: true
|
|
});
|
|
}
|