String is called immutable but in this case value of string changed. why ?

Question

?
<?php
//program to swap the string
$name1="Learner";
$name2="Programmer";
$temp=$name1 ;
$name1 =$name2 ;
$name2 =$temp;
echo "name1 =".$name1 ."<br>";
echo "name2 =".$name2 ;
?>

Answer 1

$name = "Learner";
$name[0] = "P";
// Error
This code leads to error because you can not change string that way.

Answer 2

In fact, you're not changing a string. You're assigning a new string to a variable instead.

Answer 3

thanks