how to add a default value to a javascript function variable? [duplicate]

Question

Possible Duplicate:
Is there a better way to do optional function parameters in Javascript?
Default value for function parameter?

I can I do this on javascript (jQuery) function

function somename(variableone = "content"){
 return variableone;
}

Now to access that function:

alert(somename()) //this should alert "content"
alert(somename("hello world"); //this should return "hello world"

but I get this error Uncaught SyntaxError: Unexpected token =

If this is not possible, is there a way to achieve the same result? OR most importantly is this a good (correct) practice.

dam, I searched for some time around stachoverflow and could not find that, Sorry — aurel
– aurel, Commented Aug 10, 2012 at 16:57
Obviously it is not possible, otherwise you wouldn't get a syntax error ;) — Felix Kling
– Felix Kling, Commented Aug 10, 2012 at 17:02

Oswaldo Acauan · Accepted Answer · 2012-08-10 16:58:30Z

3

function somename(variableone){
    if(typeof variableone === "undefined")
        variableone = "content"
    return variableone;
}

edited Aug 10, 2012 at 16:58

answered Aug 10, 2012 at 16:52

Oswaldo Acauan

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Esailija · Accepted Answer · 2012-08-10 16:52:49Z

2

function somename(variableone) {
    variableone = arguments.length < 1 ? "content" : variableone;
    return variableone;
}

answered Aug 10, 2012 at 16:52

Esailija

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Comments

Madara's Ghost · Accepted Answer · 2012-08-10 16:52:51Z

0

You'll need to use a condition:

function somename(variableone){
    if (typeof(variableone) === "undefined") {
        variableone = "content";
    }
    return variableone;
}

answered Aug 10, 2012 at 16:52

Madara's Ghost

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MoDFoX · Accepted Answer · 2012-08-10 16:56:08Z

0

function someName(somevar){

  somevar = somevar || "content";

  console.log(somevar);

}

someName();

This will set somevar to itself if it is not undefined, or (|| is or) "content".

answered Aug 10, 2012 at 16:56

MoDFoX

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Rajeev Sharma · Accepted Answer · 2012-08-10 17:01:44Z

0

function somename(variableone){
    return variableone = variableone ? variableone  : 'content'
}

answered Aug 10, 2012 at 17:01

Rajeev Sharma

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