C# String.IsNullOrEmpty Javascript equivalent

Question

I want to try to do string call equivalent to the C# String.IsNullOrEmpty(string) in javascript. I looked online assuming that there was a simple call to make, but I could not find one.

For now I am using a if(string === "" || string === null) statement to cover it, but I would rather use a predefined method (I keep getting some instances that slip by for some reason)

What is the closest javascript (or jquery if then have one) call that would be equal?

Answer 1

You're overthinking. Null and empty string are both falsey values in JavaScript.

if(!theString) {  alert("the string is null or empty"); } 

Falsey:

• false
• null
• undefined
• The empty string ''
• The number 0
• The number NaN

Answer 2

If, for whatever reason, you wanted to test only null and empty, you could do:

function isNullOrEmpty( s )  {     return ( s == null || s === "" ); } 

Note: This will also catch undefined as @Raynos mentioned in the comments.