how to make a loop on $this php code example

Example: how create loop php

for (initialization; condition; increment){
   code to be executed;
}
//Example
<?php
    $a = 0;
    $b = 0;
 for( $i = 0; $i<5; $i++ )
    {
        $a += 10;
        $b += 5;
    }    
echo ("At the end of the loop a = $a and b = $b" );
?>
//.......................................//
  do {
   code to be executed;
}
while (condition);
//Example
<?php
     $i = 0;
    $num = 0;
         
  do {
       $i++;
     }
         
  while( $i < 10 );
 echo ("Loop stopped at i = $i" );
?>