Conditional Statements

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.
if...else statement -use this statement if you want to execute a set of code when a condition is true and another if the condition is not true.
else if statement -is used with the if...else statement to execute a set of code if one of several condition are true.

PHP If & Else Statements

The If...Else Statement:
If you want to execute some code if a condition is true and another code if a condition is false, use the if....else statement.

Syntax:

• if (condition ) code to be executed if condition is true; else code to be executed if condition is false; 

Example :

$d=date("D");
if ($d=="Fri")
echo "Have a nice weekend!";
else
echo "Have a nice day!";


If more than one line should be executed if a condition is true/false, the lines should be enclosed within curly braces:


$d=date("D");
if ($d=="Fri")
{
echo "Hello!
";
echo "Have a nice weekend!";
echo "See you on Monday!";
}


The Else....If Statement:

If you want to execute some code if one of several conditions are true use the else if statement.


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;

PHP Switch Statement


The Switch statement in PHP is used to perform one of several different actions based on one of several different conditions.
If you want to select one of many blocks of code to be executed,use the Switch statement.
The switch statement is used to avoid long blocks of if..else if..else code.

Syntax:

switch (expression)
{
case label1:
code to be executed if expression = label1;
break;
case label2:
code to be executed if expression = label2;
break;
default:
code to be executed
if expression is different
from both label1 and label2;
}

Example:

switch ($x)
{
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";
}