Question

I defined function name as _ , defined function fn

function _(){};

function fn(){ 
    try{
       console.info(_);
    }catch(_){
       //
    } 
    return _;
}

fn(); 

in FF output _(), but IE8 output undefined, why this result?

Answer 1

EDIT @kevinpeng thanks to updating to question original version

ie7 does not support window.console (I can’t test as i don’t have it)
ie8 supports it console if you open developer tools by F12

in firefox you can use, no problem.

so not to have error in your code:

You can do this, for console.log:

function myConsole(param) {
    if (window.console && window.console.log) {
        window.console.log(param);
    }
}