Question

I am newbie about javascript.So I do not know what is the name of I looking for and How do I do it?

After you read question if you thing question title is wrong, you should change title.

I am using console.log for debugging but this is causing error if browser IE. I made below function for this problem.

var mylog=function(){
   if (devmode && window.console){
      console.log(arguments);
   }
};

mylog("debugging");

Now I want to use all console functions without error and I can do that as below.

var myconsole={
   log:function(){
        if (devmode && window.console){
          console.log(arguments);
       }
   }
   ,error:function(){
        if (devmode && window.console){
          console.error(arguments);
       }
   }

  ...
  ...
  ...


};

But I do not want to add all console functions to myconsole object severally.
I can do that in PHP with below code.

class MyConsole
{
  function __call($func,$args)
  {
     if ($devmode && function_exists('Console')){
        Console::$func($args); // Suppose that there is Console class.
     }   
  }
}

MyConsole::warn("name",$name);
MyConsole::error("lastname",$lastname);

This is possible with __noSuchMethod__ method but this is specific to only firefox.

Thanks for helping.

Answer 1

Unfortunately, you can’t do that in JavaScript, the language doesn’t have support for the “no such method” concept.

Two options for you:

Option 1:

Use strings for your method name, e.g.:

function myconsole(method) {
    var args;

    if (devmode && window.console) {
        args = Array.prototype.slice.apply(arguments, 1);
        window.console[method].apply(window.console, args);
    }
}

Usage:

myconsole("log", "message");
myconsole("error", "errormessage");

The meat of myconsole is here:

args = Array.prototype.slice.apply(arguments, 1);
window.console[method].apply(window.console, args);

The first line copies all of the arguments supplied to myconsole except the first one (which is the name of the method we want to use). The second line retrieves the function object for the property named by the string in method from the console object and then calls it via the JavaScript apply function, giving it those arguments.

Option 2:

A second alternative came to me which is best expressed directly in code:

var myconsole = (function() {

    var methods = "log debug info warn error assert clear dir dirxml trace group groupCollapsed groupEnd time timeEnd profile profileEnd count exception table".split(' '),
        index,
        myconsole = {},
        realconsole = window.console;

    for (index = 0; index < methods.length; ++index) {
        proxy(methods[index]);
    }

    function proxy(method) {
        if (!devmode || !realconsole || typeof realconsole[method] !== 'function') {
            myconsole[method] = noop;
        }
        else {
            myconsole[method] = function() {
                return realconsole[method].apply(realconsole, arguments);
            };
        }
    }

    function noop() {
    }

    return myconsole;
})();

Then you just call log, warn, etc., on myconsole as normal.