javascript double and code example

Example 1: javascript operator double not

// convert to boolean 
// The following examples are the only values which result in a false expression

!!0 // false
!!"" // false
!!null // false
!!undefined // false
!!NaN // false

Example 2: 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>