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

Take a look at the new ECMAScript Nullish coalescing operator

You can think of this feature - the ?? operator - as a way to “fall back” to a default value when dealing with null or undefined.

let x = foo ?? bar();

Again, the above code is equivalent to the following.

let x = (foo !== null && foo !== undefined) ? foo : bar();