While loop PHP

While loop in PHP, is similar to for loop, but initialization is done outside of while loop and iteration is done inside loop body.

Syntax

In PHP, while has two different syntax

initialization;
while(condition){
  // Code/set of statements
   
 iteration;
}

expr1; 
while (expr2){
    statement
 expr3;
}

initialization;
while (condition):
 // Code/set of statements
   
 iteration;
endwhile;

Second syntax uses : colon in place of opening curly brace, and endwhile keyword and semi-colon; in place of closing curly brace

While loop has four parts

initialization	Starting value or number from where while loop starts. It is the first statement and should be outside of while loop.
condition	It tests condition, if true executes the statements inside loop body, else not.
iteration	It is used to continue the while loop, until condition becomes false, It can be increment or decrement. It should be inside loop body.
Statements	These are line of codes, enclosed inside curly braces { }. single statement does not requires curly braces.

<?php

 $n = 1;
 while($n <= 10){
  echo $n;
  $n++;
}

?>

<?php

$n = 1;
while ($n <=10):
  echo $n;
  $n++;
endwhile;

?>

In second way of using while loop, in place of curly braces {}, colon : and endwhile with semicolon is used.