javascript double function code example

Example 1: double javascript

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Numbers</h2>

<p>Numbers can be written with or without decimals:</p>

<p id="demo"></p>

<script>
var x = 3.14;
var y = 3;
document.getElementById("demo").innerHTML = x + "<br>" + y;
</script>

</body>
</html>

Example 2: double function call javascript

//It means that the first function ($filter) returns another 
//function and then that returned function is called immediately. 
//For Example:
function add(x){
  return function(y){
    return x + y;
  };
}

var addTwo = add(2);

addTwo(4) === 6; // true
add(3)(4) === 7; // true