PHP statements

When the program has conditions then statements are used.
the condition means when we want to do something when something will happen, for example, there is a situation where we want to add number when number if even.'
to apply these kinds of situations in a program conditional statements are used.

There are the following types of statements.

1.  if statement
2. if-else statement
3. if-else if statement
4. nested if statement
5. switch statement
6. conditional operator statement

if statement

when the program has only one condition and related statement then if statement is used.

<?php
$n=10;
if($n%2 == 0){
echo "Even number";
}
?>

if-else statement

<?php
$n=11;
if($n%2==0){
echo "Even number";
}
else{
echo "Odd number";
}
?>

if-else-if statement

<?php
$marks=90;
if($marks > 90){
echo "Grade A";
}
else if($marks>80){
echo "Grade B";
}
else if($marks>70){
echo "Grade C";
}
else{
echo "Grade D";
}
?>

Nested if statement

when the program has a condition within other condition, there we use nested if statement.

<?php
$a=100;
$b=200;
$c=300;
if($a > $b){
  if($a > $c){
echo "A is greater.";
}
else{
echo "C is greater.";
}
}
else if($b > $a){
if($b > $c){
echo "B is greater.";
}
else{
echo "C is greater.";
}
}
?>

Switch Statement

It is an alternative statement of if-else if statement there is little difference is that relational, logical operators can not be used here.

<?php
$day=6;
switch($day){
case '1':
echo "Sunday";
break;

case '2':
echo "Monday";
break;

case '3':
echo "Tuesday";
break;

case '4':
echo "Wednesday";
break;

case '5':
echo "Tuesday";
break;

case '6':
echo "Friday";
break;

case '7':
echo "Saturday";
break;

default :
echo "Invalid number";
}
?>

Conditional operators

It is an alternative to the if-else statement, and it is an inline conditional statement.

<?php
$n=100;
$n%2 == 0 ? echo "Even number": echo "Odd number";
?>