A JavaScript function can have an optional return statement. This is required if you want to return a value from a function. This statement should be the last statement in a function.
Example
You can try to run the following code to work with return statement in JavaScript −
<html>
<head>
<script>
function concatenate(first, last) {
var full;
full = first + last;
return full;
}
function DisplayFunction() {
var result;
result = concatenate('John', ' Wright');
document.write (result );
}
</script>
</head>
<body>
<p>Click the following button to call the function</p>
<form>
<input type = "button" onclick = "DisplayFunction()" value = "Call Function">
</form>
</body>
</html>