Databases Reference
In-Depth Information
iable value itself. This allows the function to change the variable, and the main program
can use the new value. Consider Example 14-1.
Example 14-1. Passing variables to function by value and by reference
<!DOCTYPE HTML PUBLIC
"-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html401/loose.dtd">
<html>
<head>
<title>Passing variables to a function by value or by reference</title>
</head>
<body>
<table border='1'>
<tr>
<th>
Step
</th>
<th>
Variable Value
</th>
</tr>
<?php
// Set initial value for the variable
$Variable=110;
// Display the initial variable value.
echo "<tr>
<td>Initial value</td>
<td align='right'>$Variable</td>
</tr>";
// Pass the variable by value to the AddNineteen_value() function.
AddNineteen_value($Variable);
// Display the variable value after passing it by value.
echo "<tr>
<td>After passing by value</td>
<td align='right'>$Variable</td>
</tr>";
// Pass the variable by reference to the AddNineteen_reference() function.
AddNineteen_reference($Variable);
// Display the variable value after passing it by reference.
echo "<tr>
<td>After passing by reference</td>
<td align='right'>$Variable</td>
</tr>";
// Function to add 19 to the received variable;
// the function receives the variable value.
function AddNineteen_value($MyVariable)
{
$MyVariable+=19;
