How to avoid exception when checking not defined var?

Question

Simple question but i'm stuck for a while on it.

I need to check if a var is defined, before execute some taks.

So i try this

if (myVar !== null) alert('myVar is not null');

But when i do this and myVar is not defined, an exception is threw :

Uncaught ReferenceError: myVar is not defined at :1:1

So how to solve this dilema ?

score 1 · Accepted Answer · answered Jun 12 '19 at 13:12

1

You can use type of

if (typeof variable !== 'undefined') alert('myVar is not null');

answered Jun 12 '19 at 13:12

Andam

Thanks for helping instead of minus the topic. Simple solution, thanks ! :D – delphirules Jun 12 '19 at 13:15
1

@delphirules you're welcome. – Andam Jun 12 '19 at 14:00

1 Answers1