The else statement provides a default block of code that executes if the condition returned is FALSE. It cannot used by itself. It has to be together with the if statement.
if (conditional expression) {
code to be executed if condition is true;
}
else {
code to be executed if condition is false;
}
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="EN" lang="EN">
<head>
<title>PHP</title>
<meta Name="Author" Content="Hann So">
</head>
<body>
<p>
<?php
// compare a string
$wheather = "sunny";
if ($wheather == "bad") {
echo "Well today is not a $wheather day.<br />";
} else {
echo "Well I like a $wheather day.<br />";
}
// use logical operators
$temperature = 60;
if ($temperature > 74 && $temperature < 80) {
echo "We have a good temperature with $temperature degrees.<br />";
} else {
echo "$temperature degrees is not a good day.<br />";
}
?>
</p>
</body>
</html>
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You can build more complicated processes by nesting if statements within each other.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="EN" lang="EN">
<head>
<title>PHP</title>
<meta Name="Author" Content="Hann So">
</head>
<body>
<p>
<?php
$tireqty = 15;
$oilqty = 3;
$sparkqty = 3;
$totalqty = $tireqty + $oilqty + $sparkqty;
if ($totalqty == 0)
{
echo "You did not order anything.<br />";
}
else
{
if ($tireqty>0)
echo "$tireqty tires<br />";
if ($oilqty>0)
echo "$oilqty bottles of oil<br />";
if ($sparkqty>0)
echo "$sparkqty spark plugs<br />";
}
?>
</p>
</body>
</html>
|