Testing if JS Variable is set as a function parameter

Question

What is the best way to test if a javascript variable is passed a value into a function

function test(a, b) {  /* check if b was given a value */ }

I want to say

if(!b)

but this doesn't work if b = 0. Do I have to individually check if it is undefined or null like

if(typeof(b) === 'undefined' || b === null)

or is there a better way to write this?

Keith.Abramo · Accepted Answer · 2011-10-25 20:18:48Z

2

you can check the arguments property

if(arguments.length > 1){ //is there a 'b' argument
 //do stuff
}

answered Oct 25, 2011 at 20:18

Keith.Abramo

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Comments

Ben · Accepted Answer · 2011-10-25 20:16:47Z

0

I believe you can simply check for undefined:

if (b === undefined)

answered Oct 25, 2011 at 20:16

Ben

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