JavaScript Functions
JavaScript Functions
- A JavaScript function is a section of code that perform a specific task when called. Calling a function is achieved by its name.
Syntax:
function function_name() { function code } |
Example:
<html> <head> <script> function helloFunction() { alert("Hello people!"); } </script> </head> <body> <button onclick="helloFunction()">Press button</button> </body> </html> |
Calling the Function:
<script type="text/javascript"> <!-- helloFunction(); //--> </script> |
Function with Parameters:
<script type="text/javascript"> <!-- function cityFunction(city, code) { alert(city + " city code is: " + code); } //--> </script> |
Calling the Function with Parameters:
<script type="text/javascript"> <!-- cityFunction('London', 5 ); //--> </script> |
Function with a Return value:
<script type="text/javascript"> <!-- function fullname(firstname, lastname) { var name; name = firstname + lastname; return name; } //--> </script> |
Calling the Function with Return:
<script type="text/javascript"> <!-- var thename = fullname('Tom', 'Joe'); alert(thename ); //--> </script> |