Useful Debug Mode console.log messages in JavaScript

Enable console.log messages only when a variable is set to true:

var debugMode = true;

var debugLog =  function(){
    debugMode && console.log.apply( console, arguments );
  }

Now in your code, you can insert any number of debug log messages, that will be visible only when the debugMode variable is set to true.

debugLog("Ops! Debug Mode is on and there's an error !");