Conditional branching is required in programming when we need to execute some set of statements on satisfaction of a condition. PHP conditional Branching Structures are
- if structure
- if..else structure
- if…elseif structure
- switch-case structure
Simple If Structure
The Simple IF structure executes the block of statements if the condition is true. If the condition specified is false the statements after if block are executed
Syntax
if (condition)
{
If block statements
}
Statement following if structure
Example
<?php
$empName='Amy';
if ($empName=='Amy')
{
echo "Hello $empName! Please come<BR>";
}
echo "No one else is Allowed except $empName";
?>
Output:
Simple If…else Structure
The IF…ELSE structure executes the if block statements if the condition is true. If the condition specified is false the statements of else block are executed.
Syntax
if (condition)
{
if block statements
}
else
{
else block statements
}
Statement following if structure
Example
<?php
$empName='Andy';
if ($empName=='Amy')
{
echo "Hello $empName! Please come<BR>";
}
else
{
echo "No one else is Allowed except $empName";
}
?>
Output:
If…elseif structure
This structure is beneficial for nesting of IF structure to check more than one conditions.
Syntax
If (condition)
{
If statement block
}
Elseif (condition)
{
Else statement block
}
……
Else
{
Last else block
}
Example
<?php
$day='Wednesday';
if ($day=='Monday')
{
echo "Week just started! long to go<BR>";
}
elseif ($day=='Tuesday')
{
echo "Just overcame Monday Blues";
}
elseif ($day=='Wednesday')
{
echo "Half week past";
}
elseif ($day=='Thursday')
{
echo "Just keep patience for another day";
}
elseif ($day=='Friday')
{
echo "Thank God its Friday";
}
elseif ($day=='Saturday')
{
echo "Where's the party toninght>";
}
else
{
echo "Can't we have two sundays each week";
}
?>
Output:
Switch-case structure
Among PHP conditional Branching Structures, switch case structure is a better option to if…elseif structure. In a switch case structure the switch keyword is followed by the variable to be checked within parenthesis. The switch block contains various case statements followed by a possible value for the variable. The value of variable decides which statements will be executed. After each case statement block break; statement is given to stop checking of remaining case statements when one case block is executed
Syntax
Switch( Variable)
{
Case value1:
Statements
Break;
Case value2:
Statements
Break;
………..
Default:
Break
}
Example
<?php
$day='Friday';
switch($day)
{
case 'Monday':
echo "Week just started! long to go<BR>";
break;
case 'Tueday':
echo "Just overcame Monday Blues";
break;
case 'Wednesday':
echo "Half week past";
break;
case 'Thursday':
echo "Just keep patience for another day";
break;
case 'Friday':
echo "Thank God its Friday";
break;
case 'Saturday':
echo "Where's the party tonight>";
break;
default:
echo "Can't we have two Sundays each week";
break;
}
?>
Output:
