How to remove text from a string?

This doesn't have anything to do with jQuery. You can use the JavaScript replace function for this:

var str = "data-123";
str = str.replace("data-", "");

You can also pass a regex to this function. In the following example, it would replace everything except numerics:

str = str.replace(/[^0-9\.]+/g, "");

You can use "data-123".replace('data-','');, as mentioned, but as replace() only replaces the FIRST instance of the matching text, if your string was something like "data-123data-" then

"data-123data-".replace('data-','');

will only replace the first matching text. And your output will be "123data-"

DEMO

So if you want all matches of text to be replaced in string you have to use a regular expression with the g flag like that:

"data-123data-".replace(/data-/g,'');

And your output will be "123"

DEMO2

var ret = "data-123".replace('data-','');
console.log(ret);   //prints: 123

Docs.

For all occurrences to be discarded use:

var ret = "data-123".replace(/data-/g,'');

PS: The replace function returns a new string and leaves the original string unchanged, so use the function return value after the replace() call.