Very often when you write code, you want to perform different actions for different decisions. You can use conditional statements in your code to do this.
In PHP we have the following conditional statements:
- if statement - executes some code only if a specified condition is true
- if...else statement - executes some code if a condition is true and another code if the condition is false
- if...else if....else statement - selects one of several blocks of code to be executed
- switch statement - selects one of many blocks of code to be executed
PHP - The if Statement
The if statement is used to execute some code only if a specified condition is true.
Syntax
if (condition)
{
code to be executed if condition is true;
}
{
code to be executed if condition is true;
}
The example below will output "Have a good day!" if the current time is less than 20:
PHP - The if...else Statement
Use the if....else statement to execute some code if a condition is true and another code if the condition is false.
Syntax
if (condition)
{
code to be executed if condition is true;
}
else
{
code to be executed if condition is false;
}
{
code to be executed if condition is true;
}
else
{
code to be executed if condition is false;
}
The example below will output "Have a good day!" if the current time is less than 20, and "Have a good night!" otherwise:
Example
<?php
$t=date("H");
if ($t<"20")
{
echo "Have a good day!";
}
else
{
echo "Have a good night!";
}
?>
$t=date("H");
if ($t<"20")
{
echo "Have a good day!";
}
else
{
echo "Have a good night!";
}
?>
Run example »
PHP - The if...else if....else Statement
Use the if....else if...else statement to select one of several blocks of code to be executed.
Syntax
if (condition)
{
code to be executed if condition is true;
}
else if (condition)
{
code to be executed if condition is true;
}
else
{
code to be executed if condition is false; }
{
code to be executed if condition is true;
}
else if (condition)
{
code to be executed if condition is true;
}
else
{
code to be executed if condition is false; }
The example below will 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!":
Example
<?php
$t=date("H");
if ($t<"10")
{
echo "Have a good morning!";
}
else if ($t<"20")
{
echo "Have a good day!";
}
else
{
echo "Have a good night!";
}
?>
$t=date("H");
if ($t<"10")
{
echo "Have a good morning!";
}
else if ($t<"20")
{
echo "Have a good day!";
}
else
{
echo "Have a good night!";
}
?>
No comments:
Post a Comment