JavaScript and local variables bad practise?

Question

Is it bad to use local variable in the code below and if so, why?

var lib = new function () {

    var localVariable;

    this.publicCall = function (e) {
      localVariable = e.variable;
    };

    var privateCall = function (e) {
      localVariable = e.variable; 
    };
};

no, why would it be bad? it's a way to do private vars in JS — Javier, Jul 27 '12 at 13:38

score 1 · Accepted Answer · answered Jul 27 '12 at 13:39

1

No, in fact I'd say that looks like good practice.

What alternative were you thinking of? A global variable? Now that would be bad practice.

answered Jul 27 '12 at 13:39

SDC

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hmm, most times I can pass variable by injecting it into the arguments of a function I'm calling, thus using arguments as a main transport, it just looks less readable than using local vars... – user1514042 Jul 27 '12 at 13:43
Injection is good if it's preventing a dependency (ie because it makes unit testing easier), but for simple variables, there's no dependency to worry about, so no real need to inject everything. A local variable is fine. – SDC Jul 27 '12 at 15:09

score 1 · Answer 2 · edited May 23 '17 at 10:26

1

No, this is actually a preferred pattern. Local variables should always be defined in the scope in which they needed. You definitely shouldn't pollute your global scope with variables as this is considered a bad practice.

There are many resources on the web to help you understand variable scope. Check out this SO question.

edited May 23 '17 at 10:26

Community

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answered Jul 27 '12 at 13:42

Kevin Babcock

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JavaScript and local variables bad practise?

2 Answers2