Get and replace the last number on a string with JavaScript or jQuery

javascript, jquery, regex, replace

Solution

You can use the regular expression `/[0-9]+(?!.*[0-9])/` to find the last number in a string (source: http://frightanic.wordpress.com/2007/06/08/regex-match-last-occurrence/). This function, using that regex with match(), parseInt() and replace(), should do what you need:

function increment_last(v) {
    return v.replace(/[0-9]+(?!.*[0-9])/, parseInt(v.match(/[0-9]+(?!.*[0-9])/), 10)+1);
}

Probably not terribly efficient, but for short strings, it shouldn't matter.

EDIT: Here's a slightly better way, using a callback function instead of searching the string twice:

function increment_last(v) {
    return v.replace(/[0-9]+(?!.*[0-9])/, function(match) {
        return parseInt(match, 10)+1;
    });
}

Problem

If I have the string: `var myStr = "foo_0_bar_0";` and I guess we should have a function called `getAndIncrementLastNumber(str)` so if I do this: `myStr = getAndIncrementLastNumber(str); // "foo_0_bar_1"` Taking on considerations that there could be another text instead of `foo` and `bar` and there might not be `underscores` or there might be more than one `underscore`; Is there any way with `JavaScript` or `jQuery` with `.replace()` and some `RegEx`?

Original source

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