Page 107 - DCAP202_Fundamentals of Web Programming

Fundamentals of Web Programming

Notes Syntactically, you can specify a function name while creating a literal function as follows:
<script type=”text/javascript”>
<!—
var variablename = function FunctionName(Argument List){
Function Body
};
//—>
</script>
But this name does not have any significance, so worth not to use it.

8.3.2 Built-in Functions

Javascript, first introduced by Netscape, changed the static fate of the HTML web pages. Before
Javascript came into existence, HTML pages were just used to render static content. Inserting
Javascript to a web page, can give it a significant degree of interactivity and functionality. It lets
you control the behavior of the web browser and how the elements of the web page are displayed.
Most web browsers have a built in javascript interpreter. When a browser downloads an html
file that contains javascript, the javascript interpreter reacts to any script.
Javascript is an object oriented programming language. It supports the concept of objects in the
form of attributes. If an object attribute consists of function, then it is a method of that object, or
if an object attribute consists of values, then it is a property of that object.

Example:
var status=document.readyState;
readyState is a property of the document object which can contain values such as
“unintialized”,”loading”,”interactive”,”complete” whereas,
document.write(“Hello World”);
write() is a method of the document object that writes the content “Hello World” on the web
page.
There are several Javascript built-in objects such as:
 Number
 String

 RegExp
 Array
 Math

 Date
 Boolean
Each of the above objects hold several built-in functions to perform object related functionality.
Apart from these methods, Javascript provides few predefined functions which do not stick to a
particular object type but are global.

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