Is there a standard function to check for null, undefined, or blank variables in JavaScript?

Question

Is there a universal JavaScript function that checks that a variable has a value and ensures that it\'s not undefined or null? I\'ve got this code,

Answer 1

Try With Different Logic. You can use bellow code for check all four(4) condition for validation like not null, not blank, not undefined and not zero only use this code (!(!(variable))) in javascript and jquery.

function myFunction() {
    var data;  //The Values can be like as null, blank, undefined, zero you can test

    if(!(!(data)))
    {
        alert("data "+data);
    } 
    else 
    {
        alert("data is "+data);
    }
}