JavaScript Functions
JavaScript Functions
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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
}
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Example:
<html>
<head>
<script>
function helloFunction()
{
alert("Hello people!");
}
</script>
</head>
<body>
<button onclick="helloFunction()">Press button</button>
</body>
</html>
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Calling the Function:
<script type="text/javascript">
<!--
helloFunction();
//-->
</script>
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Function with Parameters:
<script type="text/javascript">
<!--
function cityFunction(city, code)
{
alert(city + " city code is: " + code);
}
//-->
</script>
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Calling the Function with Parameters:
<script type="text/javascript">
<!--
cityFunction('London', 5 );
//-->
</script>
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Function with a Return value:
<script type="text/javascript">
<!--
function fullname(firstname, lastname)
{
var name;
name = firstname + lastname;
return name;
}
//-->
</script>
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Calling the Function with Return:
<script type="text/javascript">
<!--
var thename = fullname('Tom', 'Joe');
alert(thename );
//-->
</script>
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