This is a scripting language developed by Microsoft and is based loosely on Visual Basic. Its functionality in a web environment is dependant upon either an ASP engine or the Windows Scripting Host, and must be used on a Windows hosting platform. 

-The shift() method is similar as the pop() method but the difference is that Shift method works at the beginning of the array. 

-The shift() method take the first element off of the given array and returns it. The array on which is called is then altered.

For example

var myarray = ["apple ", "banana ", "mango "]; 

console.log(myarray.shift());

console.log(myarray);

we get the following console output:

apple

["banana ", "mango "];

When we call shift() on an empty array, it will return an undefined value.

Math object has two constant : Math.PI and Math.E

Math object has following functions:

- Math.abs(val1);

It will give absolute value of val1.

- Math.max(val1,val2);

This fuction will return maximum value from val1 and val2.

- Math.random();

This function will return a random number between 0 and 1.

- Math.floor(val1)

This function will returns decimal value of val1

Arrays are created by using new Array() in Java Script.

For example : var employees = new Array();

The elements to this array is assigned as follows :

employees[0] = "Kumar"

employees[1] = "Fedrick"

Files can be read and written by using java script functions – fopen(),fread() and fwrite().

The function fopen() takes two parameters – 1. Path and 2. Mode (0 for reading and 3 for writing). The fopen() function returns -1, if the file is successfully opened.

Ex: file=fopen(getScriptPath(),0);

The function fread() is used for reading the file content.

Ex: str = fread(file,flength(file));

The function fwrite() is used to write the contents to the file.

Ex(): file = fopen("c:\MyFile.txt", 3);// opens the file for writing

fwrite(file, str);// str is the content that is to be written into the file.

NaN stands for ‘not-a-number’. The function isNaN determines the argument or the value is a NaN. The function returns true if the argument is not a number, otherwise returns false.

Windows object is top level object in Java script. It contains several other objects such as, document, history, location, name, menu bar etc., in itself. Window object is the global object for Java script that is written at client-side.

Information pertaining to the client browser and system is returned by the navigator object of JavaScript. Navigator object is the top level object for all users.

To send the characters that can not be specified in a URL should be converted into their equivalent hex encoding. To perform this task the methods encodeURI() and decodeURI() are used.

For example, the following code snippet performs the encoding of URL:

<script type="text/javascript">

          var uri = https://www.mysite.com/city?=Banglore; // original URI

          var ncodeuri=encodeURI(uri);

          document.write("<br />ncodeuri”);

          var dcodeuri = decodeURI(ncodeuri); 

          document.write(“<br>/>dcodeuri”);

</script>