Conditional Statements
In PHP we have the following conditional statements:
- if statement - use this statement to execute some code only if a specified condition is true
- if...else statement - use this statement to execute some code if a condition is true and another code if the condition is false
- if...elseif....else statement - use this statement to select one of several blocks of code to be executed
- switch statement - use this statement to select one of many blocks of code to be executed
The if Statement
Use the if statement to execute some code only if a specified condition is true.
Syntax
if (
condition)
code to be executed if condition is true;
<html>
<body>
<?php
$d=date("D");
if ($d=="Fri") echo "Have a great weekend!";
?>
</body>
</html>
Click to see output
The if...else Statement
Use the if....else statement to execute some code if a condition is true and another code if a condition is false.
Syntax
if (
condition)
code to be executed if condition is true;
else
code to be executed if condition is false;
<html>
<body>
Example:
<?php
$d=date("D");
if ($d=="Fri")
echo "Have a nice weekend!";
else
echo "Have a nice day!";
?>
Click to see output
The if...elseif....else Statement
Use the if....elseif...else statement to select one of several blocks of code to be executed.
Syntax
if (
condition)
code to be executed if condition is true;
elseif (
condition)
code to be executed if condition is true;
else
code to be executed if condition is false;
Example:
<html>
<body>
<?php
$d=date("D");
if ($d=="Fri")
echo "Have a nice weekend!";
elseif ($d=="Sun")
echo "Have a nice Sunday!";
else
echo "Have a nice day!";
?>
</body>
</html>
Click to see output
The PHP Switch Statement
Use the switch statement to select one of many blocks of code to be executed.
Syntax
switch (
n)
{
case
label1:
code to be executed if n=label1;
break;
case
label2:
code to be executed if n=label2;
break;
default:
code to be executed if n is different from both label1 and label2;
}
Example:
<html>
<body>
<?php
switch ($y)
{
case 1:
echo "Number 1";
break;
case 2:
echo "Number 2";
break;
case 3:
echo "Number 3";
break;
default:
echo "No number between 1 and 3";
}
?>
</body>
</html>
Click to see output