CODEWITHSUNDEEP
angularjs
Guillermo
Guillermo

Reputation: 1533

AngularJS - What is the best way to detect undefined null or empty value at the same time?

Sometimes I need to check a value for three conditions at the same time, null, undefined or "". Due that I haven´t found any method to do this, I coded my own and it works.

$scope.isNullOrEmptyOrUndefined = function (value) {
    if (value === "" || value === null || typeof value === "undefined") {
        return true;
    }
}

Just wanted to know if there is a better way to accomplish the same thing.

Thanks so much in advance,

Guillermo

Upvotes: 6

Views: 62049

Answers (4)

Veera
Veera

Reputation: 11

**AngularJS - What is the best way to detect undefined null or empty value at the same time?**

You can define a function or you can use inline command.

$scope.isNullOrUndefined = function(value){
   return (!value) && (value === null)
}

or 

var temp = null;
(temp) ? 'I am not null' : 'yes I am null or undefined';
"yes I am null or undefined"

var temp = undefined
(temp) ? 'I am not null' : 'yes I am null or undefined';
"yes I am null or undefined"

temp = '123123Rec'
(temp) ? 'I am not null' : 'yes I am null or undefined';
"I am not null"

Upvotes: 1

VIKAS
VIKAS

Reputation: 61

I tried the below code, it's working perfect in my angular js application.

function isValid(value) {
            return typeof value !== 'undefined';
        };

Upvotes: 0

gearsdigital
gearsdigital

Reputation: 14205

Update

As mentioned in the comments it's better to use return !value.

$scope.isValid = function(value) {
    return !value
}

Old and incomplete Answer

A proper way is simply to use angular.isDefined()

Upvotes: 6

sma
sma

Reputation: 9597

How about this? Since you seem to be returning true in those null/undefined cases:

$scope.isNullOrEmptyOrUndefined = function (value) {
    return !value;
}

http://jsfiddle.net/1feLd9yn/3/

Note that an empty array and empty object will also return false as they are truthy values. If you want the true/false return to be flip-flopped, then omit the ! before value.

Upvotes: 14

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