The ?? operator is the “null coalescing” operator in C#, but JavaScript has an operator like this, i.e. ||.
The operator || is the logical OR operator. If any of the two operands are non-zero, then the condition becomes true.
Example
Here’s how you can use the operator || with var in JavaScript −
<html> <body> <script> var a = true; var b = false; document.write("(a || b) => "); result = (a || b); document.write(result); </script> </body> </html>