How do I spit a string and test for the start of a string in javascript/jquery? [duplicate]

This question already has answers here: Closed 12 years ago.

Possible Duplicates:

Splitting in string in JavaScript

javascript startswith

Hello I have a string in javascript and I need to manipulate it. The string format is as follow

xxx_yyy

I need to:

• reproduce the behaviour of the string.StartsWith("xxx_") in c#
• split the string in two strings as I would do with string.Split("_") in c#

开发者_运维技巧

any help ?

---

There's no jQuery needed here, just plain JavaScript has all you need with .indexOf() and .split(), for example:

var str = "xxx_yyy";
var startsWith = str.indexOf("xxx_") === 0;
var stringArray = str.split("_");

You can test it out here.

---

Here you go:

String.prototype.startsWith = function(pattern) {
   return this.indexOf(pattern) === 0;
};

split is already defined as a String method, and you can now use your newly created startsWith method like this:

var startsWithXXX = string.startsWith('xxx_'); //true
var array = string.split('_'); //['xxx', 'yyy'];

---

You can easily emulate StartsWith() by using JavaScript's string.indexOf():

var startsWith = function(string, pattern){
    return string.indexOf(pattern) == 0;
}

And you can simply use JavaScript's string.split() method to split.

---

JavaScript has split built-in.

'xxx_yyy'.split('_'); //produces ['xxx','yyy']

String.prototype.startsWith = function( str ) {
  return this.indexOf(str) == 0;
}


'xxx_yyy'.startsWith('xxx'); //produces true