php if else
Conditional statements are used to perform different actions based on different conditions.
PHP Conditional Statements
Very often when you write code, you want to perform different actions for
different conditions. You can use conditional statements in your code to do this.
In PHP we have the following conditional statements:
if statement - executes some code if one condition is true
if...else statement - executes some code if a condition is true and another code if that condition is false
if...elseif...else statement - executes different codes for more than two conditions
switch statement - selects one of many blocks of code to be executed
PHP - The if Statement
The if statement executes some code if one condition is true.
Syntax
if (condition) {
code to be executed if condition is true;}
Example
Output "Have a good day!" if the current time (HOUR) is less than 20:
<?php
$t = date("H");
if ($t < "20") {
echo "Have a good day!";
}
?>
PHP - The if...else Statement
The if...else statement executes some code if a condition is true and
another code if that condition is false.
Syntax
if (condition) {
code to be executed if condition is true;
}
else {
code to be executed if condition is false;
}
Example
Output "Have a good day!" if the current time is less than 20, and "Have a
good night!" otherwise:
<?php
$t = date("H");
if ($t < "20") {
echo "Have a good day!";
}
else {
echo
"Have a good night!";
}
?>
PHP - The if...elseif...else Statement
The if...elseif...else statement executes different codes for more than two
conditions.
Syntax
if (condition) {
code to be executed if this condition is true;
}
elseif (condition) {
code to be executed if first condition is false and this
condition is true;
} else {
code to be executed if all conditions are false;
}
Example
Output "Have a good morning!" if the current time is less than 10, and
"Have a good day!" if the current time is less than 20. Otherwise it will
output "Have a good night!":
<?php
$t = date("H");
if ($t < "10") {
echo "Have a good morning!";
}
elseif ($t < "20") {
echo "Have a good day!";
} else {
echo "Have a good night!";
}
?>
PHP - The switch Statement
The switch statement will be explained in the next chapter.
PHP Exercises
Test Yourself With Exercises
Exercise:
Output "Hello World" if $a is greater than $b.
$a = 50;
$b = 10;
> {
echo "Hello World";
}