check null,empty or undefined angularjs

Question

I am creating a project using angularjs.I have variable like

$scope.test = null
$scope.test = undefined
$scope.test = ""

I want to check all null,undefined and empty value in one condition

user_8869104 · Answer

You can do simple check

if(!a) {
   // do something when `a` is not undefined, null, ''.
}

user_6869015 · Answer

A very simple check that you can do:

Explanation 1:

if (value) {
 // it will come inside
 // If value is either undefined, null or ''(empty string)
}

Explanation 2:

(!value) ? "Case 1" : "Case 2"

If the value is either undefined , null or '' then Case 1 otherwise for any other value of value Case 2.