Simple PHP Calculator using an object

This gives the same result as the previous post, however this introduces the use of an object to learn the basics of OOP in PHP .


<?php
class Calculator
{
    public $num1;
    public $num2;

    public function doAddition()
    {
        return ($this->num1+$this->num2);
    }
   
    public function doSubtraction()
    {
        return ($this->num1-$this->num2);
    }
   
    public function doMultiplication()
    {
        return ($this->num1*$this->num2);
    }
   
    public function doDivision()
    {
        return ($this->num1/$this->num2);
    }
}
?>

<html>
<head><title>PHP calculator</title></head>
<body>
    <?php
    $calculator = new Calculator();
   
        $calculator->num1 =$_POST['num1'];
        $calculator->num2 =$_POST['num2'];
        $equal = "";
   
        $submitAdd =$_POST['submitAdd'];
        $submitSub =$_POST['submitSub'];
        $submitMul =$_POST['submitMul'];
        $submitDiv =$_POST['submitDiv'];
   
        if($submitAdd!=""){
            $equal = $calculator->doAddition();
            $operation = "+";
        }
        else if($submitSub!=""){
            $equal =$calculator->doSubtraction();
            $operation = "-";
        }
        else if($submitMul!=""){
            $equal =$calculator->doMultiplication();
            $operation = "*";
        }
        else if($submitDiv!=""){
            $equal =$calculator->doDivision();
            $operation = "/";
        }
    ?>
    <form name="form1" action="" method="post">
        <p>CALCULATOR</p>
        <p>
            <input type="text" name="num1" size="1" value="<?php if($calculator->num1){ echo $calculator->num1;}?>"/>
            <input type="text" name="num2" size="1" value="<?php if($calculator->num2){ echo $calculator->num2;}?>"/>
            <input type="submit" name="submitAdd" id="button" value="add"/>
            <input type="submit" name="submitSub" id="button" value="sub"/>
            <input type="submit" name="submitMul" id="button" value="mul"/>
            <input type="submit" name="submitDiv" id="button" value="div"/>
        </p>
    </form>
    <?php
        if($equal != "") echo "$calculator->num1 $operation $calculator->num2 = $equal";
    ?>
</body>
</html>

Simple PHP Calculator

<html>
<head><title>PHP calculator</title></head>
<body>
    <?php
        $var1 =$_POST['num1'];
        $var2 =$_POST['num2'];
        $equal = "";
        $submitAdd =$_POST['submitAdd'];
        $submitSub =$_POST['submitSub'];
        $submitMul =$_POST['submitMul'];
        $submitDiv =$_POST['submitDiv'];
        if($submitAdd!=""){
            $equal =$var1+$var2;
            $operation = "+";
        }
        else if($submitSub!=""){
            $equal =$var1-$var2;
            $operation = "-";
        }
        else if($submitMul!=""){
            $equal =$var1*$var2;
            $operation = "*";
        }
        else if($submitDiv!=""){
            $equal =$var1/$var2;
            $operation = "/";
        }
    ?>
    <form name="form1" action="" method="post">
        <p>CALCULATOR</p>
        <p>
            <input type="text" name="num1" size="1" value="<?php if($var1){ echo $var1;}?>"/>
            <input type="text" name="num2" size="1" value="<?php if($var2){ echo $var2;}?>"/>
            <input type="submit" name="submitAdd" id="button" value="add"/>
            <input type="submit" name="submitSub" id="button" value="sub"/>
            <input type="submit" name="submitMul" id="button" value="mul"/>
            <input type="submit" name="submitDiv" id="button" value="div"/>
        </p>
    </form>
    <?php
        if($equal != "") echo "$var1 $operation $var2 = $equal";
    ?>
</body>
</html>

PHP Login 002

This program verifies user access and retrieves its corresponding data.

[config.php]
<?php
    $db_user = "root";  // mysql username to access the database with.
    $db_pass = "crawl";  // mysql password to access the database with.
    $database = "crawler_attendance";  // the name of the database.
    $server = "localhost";  // server to connect to.
    $table = "employees";    // the table that this script will set up and use.
    $link = mysql_connect($server, $db_user, $db_pass);
    mysql_select_db($database,$link);
?>


[index.html]

 <html>
    <head>
        <title>Php Simple Login Form</title>
        <link rel="stylesheet" type="text/css" href="style.css" />
    </head>
    <body>
        <div id="containt" align="center">
            <form action="login.php" method="post">
                <div id="header"><h2 class="sansserif">Admin/Employee Login</h2> </div>
                 <table>
                    <tr>
                        <td>Enter ID:</td>
                        <td><input type="text" name="id_num" size="10"></td>
                    </tr>
                         
                    <tr>
                        <td>Enter Password:</td>
                        <td><input type="password" name="password" size="10"></td>
                    </tr>
                    <tr>
                         <td><input type="submit" value="Log In"></td>
                    </tr>
                 </table>
            </form>
        </div>
    </body>
</html>


[login.php]

 <?php
    session_start();

    include("config.php"); //including config.php in our file
    $id_num = $_POST["id_num"]; //Storing username in $username variable.
    $password = $_POST["password"]; //Storing password in $password variable.

    $query = "select id, firstname, lastname from $table where company_id_no='".$_POST['id_num']."' and password = '".$_POST['password']."';";

    $execqry = mysql_query($query);
    $getValue = mysql_fetch_array($execqry); //place query result in an array?

    $id_firstname= $getValue['firstname'];
    $num_rows = mysql_num_rows($execqry);

    if ($num_rows <= 0) {
        echo "Sorry, incorrect credentials entered. <BR>";
        echo "Try again";
        exit;
    } else {
        $_SESSION['user']= $id_firstname;
        header("location:display.php");
        // It is the page where you want to redirect user after successful login.
    }
?>

[display.php]

<?php
session_start();
echo "Hello ". $_SESSION['user']. ".";
?>

PHP Login 001

This passes a value from one file to another file using PHP.

[exercise001.html]

<HTML>
    <HEAD>
        <TITLE> LOGIN PAGE </TITLE>
    </HEAD>
    <FORM NAME ="form1" METHOD ="POST" ACTION = "exercise002.php">
        <INPUT TYPE = "TEXT" VALUE ="username" NAME="username">
        <INPUT TYPE = "Submit" NAME= "Submit1" VALUE = "Login">
    </FORM>
</HTML>

[exercise002.php]


<HTML>
    <HEAD>
        <TITLE>A BASIC HTML FORM</TITLE>
            <?PHP
            $username = $_POST['username'];
            echo "Welcome $username.";
            ?>
    </HEAD>
</HTML>

ICloneable

I want to create an object 'b' with the same values as the original object 'a'. At runtime, the values on 'b' keep changing without altering the values of 'a'. Once successful, 'a' adopts the new values of object 'b'. Otherwise, object 'a' retains its original values.

void Main()
{
    bool success = false;

    Object a = new Object();
    Object b = (Object)a.Clone();
           
    b.anyVal = "BBB"; //at runtime
    if(success ==  true) a = (Object)b.Clone();
}

class Object : ICloneable
{
    public string anyVal { get; set; }
   
    public Object() { anyVal = "AAA";}

    public object Clone() { return this.MemberwiseClone(); }
}