Nsryjdtyk

I have checked the previous asked questions like this but for my purpose they weren't helpful.

The purpose is to perform operation on the basis of users input:

If user clicked on addition then a random sequence having only addition operation should be generated and so on.

Also user can select more than one operation at a time and accordingly output will be shown to user on basis of their choice.

The code is generating random sequence having random operands and operator with answer properly I just want to do it for selected operations which will be selected by user.

How can I do it?

Below is my code for random sequence generator, The code is working fine but for all the arithmetic operations even without selecting any checkbox after clicking on generate button.

<form action="" method="POST">

    Select no.of questions:<input type="number" name="que" value="que">

    <br /> <br />



    Select no. of Integers:

    <select name="select">

        <option value="0"> Please select </option>

        <option value="1"> 1 </option>

        <option value="2"> 2 </option>

        <option value="3"> 3 </option>

        <option value="4"> 4 </option>

        <option value="5"> 5 </option>

        <option value="6"> 6 </option>

        <option value="7"> 7 </option>

        <option value="8"> 8 </option>

        <option value="9"> 9 </option>

        <option value="10"> 10 </option>

    </select>

    <br /><br /> 



    Select number type(in digits) :

    <input type="number" name="digits" value="digits">

    <br /><br />



    Select operations:<br />

    <input type="checkbox" id="add" name="operation" value="addition"  

           onclick="doOperation()">

    <label>Addition</label>



    <input type="checkbox" id="sub" name="operation" value="subtract"  

           onclick="doOperation()">

    <label>Subtraction</label>



    <input type="checkbox" id="mult" name="operation" value="multiply" 

           onclick="doOperation()">

    <label>Multiplication</label>



    <input type="checkbox" id="div" name="operation" value="divide"  

           onclick="doOperation()">

    <label>Division</label>



    <br /><br />

    <br /><br />



    <input type="submit" name="submit" value="Generate"><br>

    <br />

</form>

Below is my php code for sequence generator, in this code I managed to do all the operations when generate button is clicked.

I also want to do it for operation that will be selected by user using checkbox. Suppose the user selected addition and multiplication or any two or any three operation then in output sequence having only those selected operations should be generate.

So how can I do that?

For clear idea you can run this code you will understand the problem.

Here is my php code

<?php

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

        if($_POST['digits'] == 1) {

            $q = $_POST['que'];



            $rOperators = array('+', '-', '*', '/');

            $previousInt = null; //Track the previous operand

            $s = $_POST['select'];



            echo "no.of questions:".$q. "<br />";

            echo  "no of digits: 1 <br />";

            echo "no. of integers:" .$s. "<br />";

            echo "Your generted sequence is below :<br /><br />";



            for ($x = 1; $x<=$q; $x++)

            {

                $randomOperands = array();

                $randomOperators = array();



                // do a loop over $i n times

                for ($i = 1; $i <=$s; $i++)

                {

                    // assign random operand to array slot

                    $nextInt = rand(0, 9);

                    $randomOperands = $nextInt;



                    if($i < $s) {

                        //No operator after last opearnd

                        if($previousInt === 0) {

                            //Make sure to avoid a potenial division-by-zero

                            $randomOperators = $rOperators[rand(0, 2)];

                        } else {

                            $randomOperators = $rOperators[rand(0, 3)];

                        } 

                    }



                    $previousInt = $nextInt;

                }



                // print array values:

                $exp = '';



                foreach($randomOperands as $key=>$value1)

                {

                    $exp .=  $value1 . " "; 



                    if(isset($randomOperators[$key])) {

                        $exp .=  $randomOperators[$key] ." "; 

                    }

                }



                $res = eval("return ($exp);");



                //print your expression

                echo ("This is Q(".$x."):"), $exp."=".$res."<br />";

            }

        } 

    ?>

I know we have to use JavaScript here for the operations but I am a beginner in this so how can I do it?