I want to know if a string starts with the specified character/string or ends with it in jQuery.
For Example:
var str = 'Hello World'; if( str starts with 'Hello' ) { alert('true'); } else { alert('false'); } if( str ends with 'World' ) { alert('true'); } else { alert('false'); } If there is not any function then any alternative ?
One option is to use regular expressions:
if (str.match("^Hello")) { // do this if begins with Hello } if (str.match("World$")) { // do this if ends in world } 
str.match(/^Hello/) But the form /regex/.test(str) is even better for this particular case, per stackoverflow.com/questions/10940137/…
var isUnavailable = $("#StatusId option:selected").text().match("^Unavailable - "); - why does this return null when the selected option is "Unavailable - Other" ?For startswith, you can use indexOf:
if(str.indexOf('Hello') == 0) { ...
and you can do the maths based on string length to determine 'endswith'.
if(str.lastIndexOf('Hello') == str.length - 'Hello'.length) { 
lastIndexOf() for the endswith ;)
("1234".lastIndexOf('Hello') == "1234".length - 'Hello'.length) results in true.There is no need of jQuery to do that. You could code a jQuery wrapper but it would be useless so you should better use
var str = "Hello World"; window.alert("Starts with Hello ? " + /^Hello/i.test(str)); window.alert("Ends with Hello ? " + /Hello$/i.test(str)); as the match() method is deprecated.
PS : the "i" flag in RegExp is optional and stands for case insensitive (so it will also return true for "hello", "hEllo", etc.).
You do not really need jQuery for such tasks. In the ES6 specification they already have out of the box methods startsWith and endsWith.
var str = "To be, or not to be, that is the question."; alert(str.startsWith("To be")); // true alert(str.startsWith("not to be")); // false alert(str.startsWith("not to be", 10)); // true var str = "To be, or not to be, that is the question."; alert( str.endsWith("question.") ); // true alert( str.endsWith("to be") ); // false alert( str.endsWith("to be", 19) ); // true Currently available in FF and Chrome. For old browsers you can use their polyfills or substr
You can always extend String prototype like this:
// Checks that string starts with the specific string if (typeof String.prototype.startsWith != 'function') { String.prototype.startsWith = function (str) { return this.slice(0, str.length) == str; }; } // Checks that string ends with the specific string... if (typeof String.prototype.endsWith != 'function') { String.prototype.endsWith = function (str) { return this.slice(-str.length) == str; }; } And use it like this:
var str = 'Hello World'; if( str.startsWith('Hello') ) { // your string starts with 'Hello' } if( str.endsWith('World') ) { // your string ends with 'World' } ES6 now supports the startsWith() and endsWith() method for checking beginning and ending of strings. If you want to support pre-es6 engines, you might want to consider adding one of the suggested methods to the String prototype.
if (typeof String.prototype.startsWith != 'function') { String.prototype.startsWith = function (str) { return this.match(new RegExp("^" + str)); }; } if (typeof String.prototype.endsWith != 'function') { String.prototype.endsWith = function (str) { return this.match(new RegExp(str + "$")); }; } var str = "foobar is not barfoo"; console.log(str.startsWith("foob"); // true console.log(str.endsWith("rfoo"); // true 
()[].) will break your polyfill methods. You need to prepare the strings with a regex-escape function. Or even better: Use a battle tested polyfill from core-js