Cannot delete object property in Javascript

Question

obj = {a: []}

I want to delete obj.a. This code works

if(!obj.a.length)
    delete obj.a //work

This is not

function _delete(o) {
    if(!o.length)
      delete o 
}

_delete(obj.a) //not work

Any way to make it works?

Solution

You can't delete [], which is all that you pass to the function.

You can create a function like

function _delete(obj, prop) {
    if (obj[prop] && ! obj[prop].length) delete obj[prop];
}

and call it with

_delete(obj, 'a');

I'd also add a check for what the property is, and if it exists at all. As you seem to target an array, add a check if it's an array that gets passed:

function _delete(obj, prop) {
    if (Array.isArray(obj[prop]) && ! obj[prop].length) delete obj[prop];
}

Comments

[charlietfl]

might want a check if property exists also so as not to throw error checking length of undefined