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>