access the last three Characters of the value in Jquery

I have a value "319CDXB" everytime i have to access last three characters of the Strring ho开发者_JS百科w can i do this . Usually the Length varies all the time .Everytime I need the last characters of the String using Jquery

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The String .slice() method lets you use a negative index:

var str = "319CDXB".slice( -3 ); // DXB

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EDIT: To expound a bit, the .slice() method for String is a method that behaves very much like its Array counterpart.

The first parameter represents the starting index, while the second is the index representing the stopping point.

Either parameter allows a negative index to be employed, as long as the range makes sense. Omitting the second parameter implies the end of the String.

Example: http://jsfiddle.net/patrick_dw/N4Z93/

var str = "abcdefg";

str.slice(0);        // "abcdefg"
str.slice(2);        // "cdefg"
str.slice(2,-2);     // "cde"
str.slice(-2);       // "fg"
str.slice(-5,-2);    // "cde"

The other nice thing about .slice() is that it is widely supported in all major browsers. These two reasons make it (in my opinion) the most appealing option for obtaining a section of a String.

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You can do this with regular JavaScript:

var str = "319CDXB";
var lastThree = str.substr(str.length - 3);

If you're getting it from jQuery via .val(), just use that as your str in the above code.

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Simple:

str = "319CDXB"
last_three = str.substr(-3)

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var str = "319CDXB";
str.substr(str.length - 3); // "DXB"