Convert to String with String() casting function

String() casting function is useful for null or undefined value. The String() function follows these rules:

ValueReturns
value with toString() methodcalled toString without arguments
null"null" string
undefined"undefined" string
 
<!DOCTYPE html>
<html>
<head>
    <title>String Example</title>
    <script type="text/javascript">

        var value1 = 1; 
        var value2 = true; 
        var value3 = null; 
        var value4; 
        document.writeln(String(value1)); //"1" 
        document.writeln(String(value2)); //"true" 
        document.writeln(String(value3)); //"null" 
        document.writeln(String(value4)); //"undefined" 

    </script>

</head>
<body>
  
</body>
</html>
Click to view the demo
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  1. JavaScript Data Types
  2. typeof Operator
  3. The Undefined Type
  4. null Type
  5. null vs undefined
  6. Boolean Type
  7. Boolean() casting function
  8. The Literials of Number Type
  9. Octal Integer
  10. Hexadecimal
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  12. Value range
  13. NaN
  14. Number Conversions:Number(), parseInt() and parseFloat()
  15. Number() function
  16. parseInt()
  17. parseFloat()
  18. The String Type
  19. String Literals and Escapes
  20. Get the String Length
  21. Converting to a String with toString() method
  22. Convert Number to String with radix
  23. Convert to String with String() casting function