Nesting Of Function

 

C Permit Nesting Of Function Freely,In Nesting Of Function One Function Can Call Another Function, Which In Term Can Call Another Function.There Is No Limit On How Deeply Function Can be Nested.
The Order In Which Function Are Define In A Program And Order In Which They Get Called Need Not Necessary Be Same.

Img Credit: Google Images

Example-:
#include<stdio.h>
#include<conio.h>
main()
{printf("\n Hello,This Is Main");
fun1();
printf("\n Hello,We Are Back In Main");
getch();
}
fun1();
{printf("\n Hello,This Is fun1");
 fun2();
printf("\n Hello,We Are Back In fun1");
}
fun2();
{printf("\n Hello,This Is fun2");
}

<?php

// Check if the form is submitted

if ($_SERVER["REQUEST_METHOD"] == "POST") {

    $errors = array();

    // Validate First Name (must be at least 3 characters long)

    if (isset($_POST['first_name'])) {

        $first_name = $_POST['first_name'];

        if (strlen($first_name) < 3) {

            $errors['first_name'] = "First name must be at least 3 characters long.";

        }

    }

    // Validate Email

    if (isset($_POST['email'])) {

        $email = $_POST['email'];

        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {

            $errors['email'] = "Invalid email format.";

        }

    }

    // Validate Password (must be at least 6 characters long)

    if (isset($_POST['password'])) {

        $password = $_POST['password'];

        if (strlen($password) < 6) {

            $errors['password'] = "Password must be at least 6 characters long.";

        }

    }

    // Validate Confirm Password (must match the Password)

    if (isset($_POST['confirm_password'])) {

        $confirm_password = $_POST['confirm_password'];

        if ($password !== $confirm_password) {

            $errors['confirm_password'] = "Passwords do not match.";

        }

    }

    // If there are no validation errors, you can process the data further

    if (empty($errors)) {

        // Process the form data, save to the database, etc.

        // You can access the validated values using the $first_name, $email, $password, and $confirm_password variables here.

        // Example: $first_name, $email, $password, $confirm_password

    }

}

?>