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PHP

jamesjones21
jamesjones21
9,260 Points
Posted by jamesjones21
jamesjones21
9,260 Points

Help with undeclared functions in PHP script

Hi I get 3 undefined errors for my forms passing information to the variables inside my PHP script:

Basically I have tried the isset() around $_POST for $valA, $valB and $operator, but when this is done the values are not passed as they should. Any help would be appreciated. 

<?php
/* -------------------  Declared Variables --------------------- */
//Gathers information passed through the textboxes

$valA = $_POST['Value_A'];
$valB = $_POST['Value_B'];
$operator = $_POST['operator'];

//this sets the variables to blank
$valA = $valB = "";
$valAerr = "";
//Answer for all
$answer = "";

/*-------------------- Declared Variables end ---------------------*/

/*-------------------- Form Validation start -----------------------*/

//Calculations set within the functions below

    //validation check if value A has an entry
    if ($_SERVER["REQUEST_METHOD"] == "POST"){
      if (empty($_POST["Value_A"])) {
        $valAerr = "Value Reqired";
        } 
    }

/*------------------ Form Validation end ----------------------------*/
/*---------------------------------- Function Start ----------------------------------*/
//Functions to be called within the switch statement based on the operator used

function add(){
    global $valA, $valB, $answer;

    $answer = $valA + $valB;
    return $answer;
}

function divide(){
  global $valA, $valB, $answer;

 $answer = $valA / $valB;
    return $answer;
}

function multi(){
  global $valA, $valB, $answer;

    $answer = $valA * $valB ;
    return $answer;
}


function subtract(){
  global $valA, $valB, $answer;

    $answer = $valA - $valB;
    return $answer;

}

/*----------------------- Function end ---------------------------------*/


/*----------------------- Switch Statement Start ------------------------*/
//switch statement to determine which function to call and to return the answer

switch ($operator){

  case "+":
      echo add();
      break;

  case "-":

   echo subtract();
   break;

  case "*":
    echo multi();
    break;

  case "/":
  echo divide();
  break;

  default:
  echo "Require an answer";
}

/*------------------------------------- Switch Statement End ----------------------------*/

?>

<!--- forms html --->

<form action="" method="post"><!-- need to define a php script to go here -->
        <label>Value A:<?php echo $valAerr; ?></label> <input type="text" name="Value_A"/>
    <label>Add an operator</label> <input type="text" name="operator"/>
        <label> Value B:</label> <input type="text" name="Value_B"/><br/><br/>
        <label>Answer:</label><?php echo $answer;?><!--<input type="text" name="Answer">--><br/><br/>
      <label>Value A: <?php echo $valA; ?></label><br/>
      <label>Value B: <?php echo $valB; ?></label><br/>
      <label>Operator: <?php echo $operator; ?></label><br/>
        <input type="submit" name="Get Answer" value="Get Answer">
    </form>

1 Answer

jamesjones21
jamesjones21
9,260 Points
jamesjones21
jamesjones21
9,260 Points

altered code to check if values were set in the form ready to except data into the PHP script:

updated code:

<?php

//this sets the variables to blank
$valA = $valB = "";
$valAerr = "";
//Answer for all
$answer = "";
$operator="";

//Gathers information passed through the textboxes
if (isset($_POST['Value_A'])){
$valA = $_POST['Value_A'];

    if (isset($_POST['Value_B'])){
    $valB = $_POST['Value_B'];

            if (isset($_POST['operator'])){
            $operator = $_POST['operator'];
        }
    }
}



//Calculations set within the functions below

    //validation check if value A has an entry
    if ($_SERVER["REQUEST_METHOD"] == "POST"){
      if (empty($_POST["Value_A"])) {
        $valAerr = "Value Reqired";
        } 
    }


//Functions to be called within the switch statement based on the operator used

function add(){
    global $valA, $valB, $answer;

    $answer = $valA + $valB;
    return $answer;
}

function divide(){
  global $valA, $valB, $answer;

 $answer = $valA / $valB;
    return $answer;
}

function multi(){
  global $valA, $valB, $answer;

    $answer = $valA * $valB ;
    return $answer;
}


function subtract(){
  global $valA, $valB, $answer;

    $answer = $valA - $valB;
    return $answer;

}


//switch statement to determine which function to call and to return the answer

if(isset($_POST['operator'])){
  switch ($operator){

  case "+":
      echo add();
      break;

  case "-":

   echo subtract();
   break;

  case "*":
    echo multi();
    break;

  case "/":

  echo divide();
  break;

  default:
  echo "Require an answer";
  }
}

?>