javascript accessing the name of the parameters for debugging purposes

Question

is there anyway to access the "name" of the parameter as such:

function(arg1, arg2) {
    debug("arg1 is rotten!");
}

Right now if i change the parameter name I'd have to change the name within the string as well, so I was looking if javascript had a solution like How do i bind function arguments to the parameters i supply in creating an ArgumentException object?

I want a way to be able to do something like:

function(arg1, arg2) {
        debug(arguments[0].name+" is rotten!");
    }

so that I would not have to search for the changes and change accordingly whenever i change the name of the parameter (sometimes its used more than once!)

To get the first arguments, you can use `arguments[0]` etc. The name then doesn't matter. (But then again the order is important, of course) — pimvdb, May 20 '11 at 14:44
Maybe I misunderstand your problem.. but that's completely normal that you have to change code if you change a parameter name unless that parameter is not used answhere.. — ThiefMaster, May 20 '11 at 14:44

score 3 · Accepted Answer · answered May 20 '11 at 15:04

You cannot access variable names, only their values. The closest you can get is if your argument to your method is an 'options' style object (which is just a regular JavaScript object, but calling it 'options' or 'opts' and having that contain all your arguments is a very common practice):

function test(opts){
    for(var name in opts){
        console.log(name + ' with value ' + opts[name] + ' is rotten!')
    }
}

test({arg1: 'argument 1', arg2: 'argument 2'});

score 1 · Answer 2 · answered May 20 '11 at 14:43

1

Whenever you have a function, there is an array in the function called arguments that holds all the arguments in it

see fiddle: http://jsfiddle.net/maniator/P5FvN/

answered May 20 '11 at 14:43

Naftali

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1

I think he actually wants the name of the variable, not just access to it's value in arguments – Matt May 20 '11 at 15:02
@Matt +10 for understanding the question – Pacerier May 20 '11 at 15:12
wasn't me, but I'm guessing it's because you didn't actually answer the question. – CoolUserName May 20 '11 at 15:34
@user90070, well there is no way to actually get the arguments names unless u did a hack like @Matt has done in his answer – Naftali May 20 '11 at 15:35

score 0 · Answer 3 · answered May 20 '11 at 14:58

0

try this :

function show_me() {
    for (var i=0; i < arguments.length; i++) {
        alert(arguments[i]);
    }
}

show_me('a', 'b');

answered May 20 '11 at 14:58

Shanison

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you may want to read this http://stackoverflow.com/questions/1009911/javascript-get-argument-value-and-name-of-passed-variable – Shanison May 20 '11 at 15:40

javascript accessing the name of the parameters for debugging purposes

3 Answers3