Question

I was doing some refactoring and wanted to break into the debugger and return before getting to a piece of code that made permanent changes so I put in one of my functions

return debugger;

And I got an unexpected token error (in chrome).

debugger;
return;

works just fine. Is there something in the ECMAScript spec that actually specifies this as correct behavior? Is this a browser bug? Is there any particular logic to this failing at all?

Answer 1

return is optionally followed by an Expression, which when evaluated becomes the result to return. debugger is not an expression, it’s a Statement. So return debugger; fails for the same reason return for (i = 0; i < 10; ++i);, return if (a > b);, etc. fail — because you can’t use statements as expressions.