Really basic javascript function concept

Question

Testing my ability to write code in JavaScript and Node (perhaps a bit of a monumental effort) and also attempting to understand standards.

I want to dynamically change an attribute in an object as in this examnple:

    var parms = {
        host:'',
        port:'',
        user:'',
        pass:''
    };
    
    parms.user='foo';
    parms.pass='bar';
    console.log(parms.user);
    setParm = function(param,value){
        parms.param = value;
    }
    
    setParm('user','baz');
    console.log(parms.user);

However, I'm completely blind. I feel as though I may be in a blind alley in terms of what I think is possible versus what is actually workable.

See [*MDN Property accessors*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Property_Accessors). — RobG, Jul 29 '17 at 00:31
@BekimBacaj—that's a red herring. The OP wants to know how to access a property using the value of a variable. [Setters](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/set) and [getters](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get) don't help with that, they're a completely different concept. — RobG, Jul 29 '17 at 00:45
@kenIngram: you seem to want to learn the fundamentals, so although not explicitly asked let me recommend these online and free books. http://eloquentjavascript.net/ (beginner) , https://github.com/getify/You-Dont-Know-JS (intermediate / advanced) . Takes a couple of weeks but this is (arguably) the best stuff that's out there. Good luck! — Geert-Jan, Jul 29 '17 at 00:48
Thanks. I did Codeschool a while back and alot of it got in, but not much stuck. Also, this question arose because I was working on creating getters and setters. — Ken Ingram, Jul 29 '17 at 05:25
@KenIngram Remember you can accept a solution if it answered your question! — cs95, Jul 31 '17 at 13:13

score 1 · Accepted Answer · answered Jul 29 '17 at 00:18

You are passing the property as a string, so accessing with . won't work. One solution I know is that you can use dict-like indexing:

    var parms = {
        host:'',
        port:'',
        user:'',
        pass:''
    };
    
    parms.user='foo';
    parms.pass='bar';
    console.log(parms.user);
    setParm = function(param,value){
        parms[param] = value;
    }
    
    setParm('user','baz');
    console.log(parms.user);

Really basic javascript function concept

1 Answers1