if
, else
and else if
Conditional StatementsWhile writing programs/scripts, there will be scenarios where you would want to execute a particular statement only if some condition is satisfied. In such situations we use Conditional statements.
In PHP, there are 4 different types of Conditional Statements.
if
statementsif...else
statementsif...elseif...else
statementsswitch
statementWe will cover the switch
statements in the next tutorial.
if
statementWhen we want to execute some code when a condition is true, then we use if
statement.
Syntax:
if(condition)
{
// code to be executed if 'condition' is true
}
Here is a simple example,
<?php
$age = 20;
if($age <= 25)
{
echo "You are not allowed to consume alchohol";
}
?>
if...else
statementWhen we want to execute some code when a condition is true, and some other code when that condition is false, then we use the if...else
pair.
Syntax:
if(condition)
{
// code to be executed if 'condition' is true
}
else
{
// code to be executed if 'condition' is false
}
Here is a simple example,
<?php
$age = 26;
if($age <= 25)
{
echo "You are not allowed to consume alchohol";
}
else
{
echo "Enjoy the drinks";
}
?>
Enjoy the drinks
if...else...elseif
statementWhen we want to execute different code for different set of conditions, and we have more than 2 possible conditions, then we use if...elseif...else
pair.
Syntax:
if(condition1)
{
// code to be executed if 'condition1' is true
}
elseif(condition2)
{
// code to be executed if 'condition2' is true
}
else
{
/* code to be executed if both 'condition1'
and 'condition2' are false */
}
Here is a simple example,
<?php
// speed in kmph
$speed = 110;
if($speed < 60)
{
echo "Safe driving speed";
}
elseif($speed > 60 && $speed < 100)
{
echo "You are burning extra fuel";
}
else
{
// when speed is greater than 100
echo "Its dangerous";
}
?>
Its dangerous
In the example above, we have also used logical operator &&
. Logical operators are very useful while writing multiple conditions together.
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