Question

I have PHP function inside a class that returns a math problem:

public function level1() {

    //level 1 and 2
    //single digit addition and subtraction
    //randomly choose addition or subtraction
    //1 = addtion, 2 - subtraction
    $opperand = rand( 1, 2 );

    //if the problem is a subtraction, the program will keep generating problems if a negative problem is generated
    //if opperand is a subtraction, do generate both numbers while the answer is negative

    if ( $opperand == 2 )
        {
        do {

            //randomly generate first number
            $number1 = rand( 1, 9 );

            //randomly generate second number
            $number2 = rand( 1, 9 );

            //compute the answer
            $answer = $number1 - $number2;

            //change variable to actual opperand
            $opperand = "-";
        } while ( $answer < 0 );
        }
    else
        {//addition problem
        //randomly generate first number
        $number1 = rand( 1, 9 );

        //randomly generate second number
        $number2 = rand( 1, 9 );

        //compute the answer

        $answer = $number1 + $number2;

        //change variable to actual opperand
        $opperand = "+";
        }//end if/else

    return array( $number1 . " " . $opperand . " " . $number2 . " ", $answer );

I call this function from ajaxHandler.php (Which I call from ajax)

   $problemData = $MathEngine->level1();
    return $problemData;

The php will always return an array, but I cannot figure out how to manipulate or even view the results as an array in javascript. Is there a way to do this? I’ve used the standard Get ajax call before so that’s not new. when I try to reference the ajax response text as an array, I either get nothing (when i click the button) or ‘undefined’

           var problemData = ajaxRequest.responseText;

           alert( problemData[0] )

Answer 1

// php - this will produce a json string
echo json_encode(array( $number1 . " " . $opperand . " " . $number2 . " ", $answer ));

// and in javascript - parse json string to javascript object
var problemData = JSON.parse(ajaxRequest.responseText);