How to use if else, nested if else condition in php 7?

If else condition is very useful i will also display you real world example of if else

<?php
$a= 2;
if($a == 2){
  echo "right";
}else{
  echo "wrong";
}
 ?>

Result :

Nested if else 

<?php

$percentage  = 70;

if($percentage >= 60){

  echo "first class";

}elseif ($percentage >= 50){

  echo "second class";

}elseif($percentage >= 35){

  echo "pass class";

}else{

  echo "fail";

}

 ?>

Result : first class 

 

Real world example : here I have used in my project, when process success it will display message with bootstrap theme 

You can see how i have used if condition in my project, Thank you