When and why to 'return false' in JavaScript?


I'm guessing that you're referring to the fact that you often have to put a 'return false;' statement in your event handlers, i.e.

<a href="#" onclick="doSomeFunction(); return false;">...

The 'return false;' in this case stops the browser from jumping to the current location, as indicated by the href="#" - instead, only doSomeFunction() is executed. It's useful for when you want to add events to anchor tags, but don't want the browser jumping up and down to each anchor on each click


When and why to return false in JavaScript?

return false using only if you have some worng in function (by some test) or you want to stop some function, example use return false in end "onsubmit"

Er ... how about in a boolean function to indicate 'not true'?

When you want to trigger javascript code from an anchor tag, the onclick handler should be used rather than the javascript: pseudo-protocol. The javascript code that runs within the onclick handler must return true or false (or an expression than evalues to true or false) back to the tag itself - if it returns true, then the HREF of the anchor will be followed like a normal link. If it returns false, then the HREF will be ignored. This is why "return false;" is often included at the end of the code within an onclick handler.

When using jQuery's each function, returning true or false has meaning. See the doc