产生新变量以在函数外部使用的函数 - PHP

How would I alter the function below to produce a new variable for use outside of the function?

PHP Function

    function sizeShown ($size)
    {
        // *** Continental Adult Sizes ***
        if (strpos($size, 'continental-')!== false)
        {
            $size = preg_replace("/\D+/", '', $size);
            $searchsize = 'quantity_c_size_' . $size;            
        }

      return $searchsize;

Example

<?php
    sizeShown($size);
    $searchsize;  
?>

This currently produces a null value and Notice: undefined variable.

So the function takes one argument, a variable containing a string relating to size. It checks the variable for the string 'continental-', if found it trims the string of everything except the numbers. A new variable $searchsize is created which appends 'quantity_c_size_' to the value stored in $size.

So the result would be like so ... quantity_c_size_45

I want to be able to call $searchsize outside of the function within the same script.

Can anybody provide a solution? Thanks.

Try using the global keyword, like so:

function test () {
    global $test_var;
    $test_var = 'Hello World!';
}

test();
echo $test_var;

However, this is usually not a good coding practice. So I would suggest the following:

function test () {
    return 'Hello World!';
}

$test_var = test();
echo $test_var;

In the function 'sizeShown' you are just returning the function. You forgot to echo the function when you call your function.

echo sizeShown($size);

echo $searchsize;  

?>

But the way you call $searchsize is not possible.