Page 111 - DCAP202_Fundamentals of Web Programming
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Fundamentals of Web Programming
Notes
Did u know? unescape() method is used to decode the encoded strings.
Notes Use of eval method is not advised for the following reasons:
security risk
debugging may be difficult
may result at resource hog since each invocation of eval() creates a new instance of
Javascript interpreter.
8.3.3 User-defined Functions
An user-defined function saves us from rewriting the same code again and again and helps us to
make our application smaller. The given examples will help you to understand how can you put
them to work.
JavaScript has so many built-in functions, besides that you can make your own as per the need.
General structure of the user defined function is:
function function_name(par1, par2,..){ statement}
par1, par2 are the name of the parameter, one function could have one, more than one or no
parameter. Parameters could be of any datatype.
Example (Simple Function):
<html>
<head>
<title>Write your title here </title>
<script type=”text/javascript” >
function display()
{
document.write(“Hello there”);
}
display();
</script>
</head>
</html>
Output:
Hello there
8.3.4 Calling Functions
You can call the function from any other JavaScript. After the function is executed, the other
script that called it goes on from the call.
alert(‘Example 1: the House’);
example(1,’house’);
(do more stuff)
So this script first generates an alert box, then calls the function and after the function is finished
it continues to do the rest of the instructions in the calling code.
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