How to check if 'debugger;' keyword exists?

Question

Sometimes some developers forgot to remove debugger; in javascript code, and it produce javascript error on IE. How can you check (like for the console: if(wi

Answer 1

You could attempt to compile a function that declares debugger as a local variable. If debugger is reserved as a keyword, the JS engine will throw an error which you can catch.

var debuggerIsKeyword = false;
try {
    new Function("var debugger;");
} catch(e) {
    debuggerIsKeyword = true;
}

However I'm not sure that knowing whether a keyword exists or not is actually helpful.