I am new in php, I am solving one task. Create a form with 2 text fields to enter only numbers (treat) and will mean number and power. After pressing the button the result is displayed on the same page, and the result is determined by recursive function in case you forget to enter a number, the number 2 will

Use php function in php form

I am new in php, I am solving one task.

Create a form with 2 text fields to enter only numbers (treat) and will mean number and power.
After pressing the button the result is displayed on the same page, and the result is determined by recursive function
in case you forget to enter a number, the number 2 will be inserted automatically.

I have this for now, but I don’t know how to proceed. Can you advise me please?

<!DOCTYPE html>
<html>
<head>
    <title>Task</title>
</head>
<body>
<form method="post">  
Input number:  
<input type="number" name="number1" /><br><br>  
Input power:  
<input type="number" name="number2" /><br><br>  
<input  type="submit" name="submit" value="Submit">  
</form>  
<?php 
    header("Content-Type: text/html; charset=windows-1250");
    if(isset($_POST['submit']))  
    {  
        $number1 = $_POST['number1'];  
        $number2 = $_POST['number2'];
        echo(pow($number1,$number2) . "<br>");
    }
         
?>  

 
</body>
</html>

JavaScript
​x
 
<!DOCTYPE html><html><head>    <title>Task</title></head><body><form method="post">  Input number:  <input type="number" name="number1" /><br><br>  Input power:  <input type="number" name="number2" /><br><br>  <input  type="submit" name="submit" value="Submit">  </form>  <?php     header("Content-Type: text/html; charset=windows-1250");    if(isset($_POST['submit']))      {          $number1 = $_POST['number1'];          $number2 = $_POST['number2'];        echo(pow($number1,$number2) . "<br>");    }         ?>  ​ </body></html>​

Answer

I think you are missing a key concept here. What is recursion.

A recursive function is a function that calls itself during its execution. https://en.wikipedia.org/wiki/Recursion_(computer_science)

For your question this is an acceptable solution I believe:

<!DOCTYPE html>
<html>
<head>
    <title>Task</title>
</head>
<body>
<form method="post">
    Input number:
    <input type="number" name="number1" /><br><br>
    Input power:
    <input type="number" name="number2" /><br><br>
    <input  type="submit" name="submit" value="Submit">
</form>
<?php

function pow_recursion($number, $power) {
    if ($power == 0) {
        return 1;
    } else {
        return $number * pow_recursion($number, $power - 1);
    }
}

if(isset($_POST['submit']))
{
    $number1 = $_POST['number1'];
    $number2 = $_POST['number2'];

    if (!$number2) {
        $number2 = 2;
    }

    echo(pow_recursion($number1, $number2) . "<br>");
}

?>


</body>
</html>

JavaScript
 
<!DOCTYPE html><html><head>    <title>Task</title></head><body><form method="post">    Input number:    <input type="number" name="number1" /><br><br>    Input power:    <input type="number" name="number2" /><br><br>    <input  type="submit" name="submit" value="Submit"></form><?php​function pow_recursion($number, $power) {    if ($power == 0) {        return 1;    } else {        return $number * pow_recursion($number, $power - 1);    }}​if(isset($_POST['submit'])){    $number1 = $_POST['number1'];    $number2 = $_POST['number2'];​    if (!$number2) {        $number2 = 2;    }​    echo(pow_recursion($number1, $number2) . "<br>");}​?>​​</body></html>​

Another implementation of the recursive function is

function pow_recursion($number, $power) {
    if ($power == 0) {
        return 1;
    } elseif ($power % 2 == 0) {
        $tmp = pow_recursion($number, intdiv($power, 2));
        return $tmp * $tmp;
    } else {
        return $number * pow_recursion($number, $power - 1);
    }
}

JavaScript
 
function pow_recursion($number, $power) {    if ($power == 0) {        return 1;    } elseif ($power % 2 == 0) {        $tmp = pow_recursion($number, intdiv($power, 2));        return $tmp * $tmp;    } else {        return $number * pow_recursion($number, $power - 1);    }}​

If I am not mistaken the difference in performance is N vs log(N).

Advertisement

Answer