Add content for PHP strings (#27489)

* Add content for PHP strings

* fix: resolved conflict

mock-guide/english/php/loops/while-loop/index.md

@@ -0,0 +1,47 @@
+---
+title: While Loop
+---
+## While Loop
+
+The `while loop` is one of the easiest type of loop in PHP. It executes the block of statements until the expression evaluates to **TRUE**. If the value of the expression changes at the time of execution, then the loop runs until the expression evaluates to **FALSE**.The Basic Form of While Loop is given below:
+
+```shell
+while (expr)
+    statement
+```
+The Statements inside the while loop can be enclosed within the curly braces or can be used based on the following syntax:
+
+```shell
+while (expr):
+    statement
+    ...
+endwhile;
+```
+Illustrating the simple and alternate syntax of while loop using example:
+
+```php
+<?php
+
+/* using the simple form of while loop */
+
+$i = 1;  /* initialisation part */
+
+while ($i <= 100 && $i!=5 ) 
+{
+    echo $i++;  
+}
+
+/*using the alternate synatx of while loop*/
+
+$i = 0;
+
+while ($i <= 10):
+    echo $i++;
+endwhile;
+
+?>
+```
+
+#### More Information
+
+[While loop - PHP Documentation](http://php.net/manual/en/control-structures.while.php)