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Open Source Technologies

Notes The following example function accepts one argument, $x, and returns its square:
Example: function square ($x)

{

return $x*$x;
}

After defining this function, it can be used as an expression wherever you desire.
For example:

print ‘The square of 5 is ‘ . square(5);

7.2 Function Scope

Every function has its own set of variables. Any variables used outside the function’s definition
are not accessible from within the function by default. When a function starts, its function
parameters are defined. When you use new variables inside a function, they are defined within
the function only and don’t hang around after the function call ends. In the following example,
the Variable $var is not changed by the function call:
Example: function func ( )
{

svar = 2;
}

$var = 1;
func( );
print $var;

When the function func is called, the variable $var, which is assigned 2, is only in the scope of
the function and thus does not change $var outside the function. The code snippet prints out 1.

Now hat if you actually do want to access and/or change $var on the outside? As mentioned
in the “Variables” section, you can use the built-in $ GLOBALS[] array to access variables in
the global scope of the script
Rewrite the previous script the following way:

Function func ()
{
$ GLOBALS[“var”] = 2;

}
$var = 1;
func ( );

print $var;
It prints the value 2.

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