JavaScript or jQuery string ends with utility function

Question

what is the easiest way to figure out if a string ends with a certain value?

Answer 1

I am just expanding on what @luca-matteis has posted but to solve the issues pointed out in the comments the code should be wrapped to make sure you are not overwriting a native implementation.

if ( !String.prototype.endsWith ) {  
    String.prototype.endsWith = function(pattern) {
        var d = this.length - pattern.length;
        return d >= 0 && this.lastIndexOf(pattern) === d;
    };
}

This is the suggested method for the Array.prototype.forEach method pointed out in the mozilla developer network

Answer 2

I had no luck with the match approach, but this worked:

If you have the string, "This is my string." and wanted to see if it ends with a period, do this:

var myString = "This is my string.";
var stringCheck = ".";
var foundIt = (myString.lastIndexOf(stringCheck) === myString.length - stringCheck.length) > 0;
alert(foundIt);

You can change the variable stringCheck to be any string to check for. Better still would be to throw this in your own function like this:

function DoesStringEndWith(myString, stringCheck)
{
    var foundIt = (myString.lastIndexOf(stringCheck) === myString.length - stringCheck.length) > 0;
    return foundIt;
}

Answer 3

Regular expressions

"Hello world".match(/world$/)

Answer 4

ES6 supports this directly:

'this is dog'.endsWith('dog')  //true

Answer 5

you could use Regexps, like this:

str.match(/value$/)

which would return true if the string has 'value' at the end of it ($).

Answer 6

You can always prototype String class, this will work:

String.prototype.endsWith = function(str) {return (this.match(str+"$")==str)}

You can find other related extensions for String class in http://www.tek-tips.com/faqs.cfm?fid=6620