Selection IF-ELSEIF-ELSEIF...-ELSE example

<?php

   $number=77;

   if($number>=90 && $number<=100){

       echo "A";
 
   }else if($number>=80 && $number<=89){
     
      echo "B";

   }else if($number>=70 && $number<=79){
    
      echo "C";

   }else{

      echo "D";
    }


?>