I want to share some Javascript prototype functions as below:
String.prototype.format = function (n, x, s, c) {
/// <summary>
/// Number.prototype.format(n, x, s, c)
/// Example:
/// 12345678.9.format(2, 3, ',', '.'); // "12,345,678.90"
/// 123456.789.format(4, 4, ' ', ':'); // "12 3456:7890"
/// 12345678.9.format(0, 3, '-'); // "12-345-679"
/// </summary>
/// <param name="n" type="type">length of decimal</param>
/// <param name="x" type="type">length of whole part</param>
/// <param name="s" type="type">sections delimiter</param>
/// <param name="c" type="type">decimal delimiter</param>
/// <returns type=""></returns>
var re = '\\d(?=(\\d{' + (x || 3) + '})+' + (n > 0 ? '\\D' : '') + ')';
// console.log(this.toString());
if (this.toString()) {
var item = this.toString().replace(/,/g, '');
var num = Number(item).toFixed(Math.max(0, ~~n));
return (c ? num.replace('.', c) : num).replace(new RegExp(re, 'g'), '&' + (s || ','));
}
return '';
};
String.prototype.replaceAll = function (search, replacement) {
/// <summary>
/// Replace all string in js
/// </summary>
/// <param name="search" type="type"></param>
/// <param name="replacement" type="type"></param>
/// <returns type=""></returns>
var target = this;
return target.replace(new RegExp(search, 'g'), replacement);
};
String.prototype.startsWith = function (word) {
/// <summary>
/// check whether starts With the word
/// </summary>
/// <param name="word" type="type"></param>
/// <returns type=""></returns>
return (this.indexOf(word) == 0);
};
//js startsWith function
String.prototype.endsWith = function (word) {
/// <summary>
/// check whether ends with the word
/// </summary>
/// <param name="word" type="type"></param>
/// <returns type=""></returns>
return str.indexOf(word, str.length - word.length) !== -1;
};
Date.prototype.addMonths = function (m) {
/// <summary>
/// Add months for date object
/// </summary>
/// <param name="m" type="type"></param>
/// <returns type=""></returns>
var d = new Date(this);
var years = Math.floor(m / 12);
var months = m - (years * 12);
if (years) d.setFullYear(d.getFullYear() + years);
if (months) d.setMonth(d.getMonth() + months);
return d;
}
Date.prototype.addDays = function (days) {
/// <summary>
/// Add days for date object
/// </summary>
/// <param name="days" type="type"></param>
/// <returns type=""></returns>
var dat = new Date(this.valueOf());
dat.setDate(dat.getDate() + days);
return dat;
}
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find
// find the element in array
// e.g
//var currItem = dataSource.find(function (ds) {
// return ds.startDate.getTime() == date.getTime()
//});
if (!Array.prototype.find) {
Object.defineProperty(Array.prototype, 'find', {
value: function (predicate) {
// 1. Let O be ? ToObject(this value).
if (this == null) {
throw new 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 new 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;
}
});
}
if (!Number.prototype.padLeft) {
Number.prototype.padLeft = function (n, str) {
/// <summary>
/// pad left with 0
/// e.g. console.log((23).padLeft(5)); //=> '00023'
/// </summary>
/// <param name="n" type="type"></param>
/// <param name="str" type="type"></param>
/// <returns type=""></returns>
return (this < 0 ? '-' : '') +
Array(n - String(Math.abs(this)).length + 1)
.join(str || '0') +
(Math.abs(this));
}
}
// https://tc39.github.io/ecma262/#sec-array.prototype.includes
if (!Array.prototype.includes) {
Object.defineProperty(Array.prototype, 'includes', {
value: function (searchElement, fromIndex) {
if (this == null) {
throw new TypeError('"this" is null or not defined');
}
// 1. Let O be ? ToObject(this value).
var o = Object(this);
// 2. Let len be ? ToLength(? Get(O, "length")).
var len = o.length >>> 0;
// 3. If len is 0, return false.
if (len === 0) {
return false;
}
// 4. Let n be ? ToInteger(fromIndex).
// (If fromIndex is undefined, this step produces the value 0.)
var n = fromIndex | 0;
// 5. If n ≥ 0, then
// a. Let k be n.
// 6. Else n < 0,
// a. Let k be len + n.
// b. If k < 0, let k be 0.
var k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);
function sameValueZero(x, y) {
return x === y || (typeof x === 'number' && typeof y === 'number' && isNaN(x) && isNaN(y));
}
// 7. Repeat, while k < len
while (k < len) {
// a. Let elementK be the result of ? Get(O, ! ToString(k)).
// b. If SameValueZero(searchElement, elementK) is true, return true.
if (sameValueZero(o[k], searchElement)) {
return true;
}
// c. Increase k by 1.
k++;
}
// 8. Return false
return false;
}
});
}
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