我如何使我的单选按钮工作与if语句进行计算


How do I make my radio buttons work with if statements for calculations?

所以对于一个类作业,我们使用HTML和PHP做一个表单,要求用户输入两(2)个数字,并使用单选按钮选择加法,减法,乘法或除法的形式,然后输入一个猜测的答案是什么。我们的任务是向用户回显他们的答案是否正确。

我遇到麻烦的部分是在"if"answers"else"语句中。例如,如果我选择1和2作为我的数字,猜测3并选择加法作为我的计算方法,我不仅会得到"祝贺!但我也从除法、减法和乘法中得到else语句,说明我做错了。

下面是我的代码:(记住——生日函数还没有完成。)此外,我在表单验证方面遇到了困难——使用户实际上已经输入了所需的字段。

<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>Howdy</title>
</head>
<body>
<h1>PHP_SELF</h1>
<?php

//process the form if the submit button was pressed
if (isset($_POST['submit'])) {
//form validation goes here

/////////////////////////////////////////VARIABLES ARE BEING MADE HERE
//simplify the form variables
//later on we will do this in form validation
//create a variable called firstname and store in it
//the value from the POST array for firstname from the form
$firstname = $_POST['firstname'];
//creating variables for num1 and num2 that user inputed
$num1 = $_POST['num1'];
$num2 = $_POST['num2'];
//creating a variable called sum
//this is for when the user chooses to ADD 
//num1 and num2
$sum = $num1 + $num2;
//creating a variable called difference
//this is for when the user chooses to SUBTRACT
//num1 and num2
$difference = $num1 - $num2;
//creating a variable called product
//this is for when the user chooses to MULTIPLY
//num1 and num2
$product  = $num1 * $num2;
//creating a variable called quotient
//this is for when the user chooses to DIVIDE
//num1 and num2
$quotient = $num1 / $num2;
//creating a variable called guess and store it in the
//value from the POST array for the guess from the form
$guess = $_POST['guess'];
//creating a variable called birthday and store it in the
//value from the POST array for the user's birthday
$birthday = $_POST['birthday'];

if ($sum == $guess) {
echo "<p>Congratulations $firstname. You answered correctly with $guess.<p>'n";
} else if ($sum != $guess){
echo "<p>$firstname, you answered incorrectly. The correct answer is $sum.</p>'n";
} 

if ($difference == $guess) {
echo "<p>Congratulations $firstname. You answered correctly with $guess.<p>'n";
} else if ($difference != $guess){
echo "<p>$firstname, you answered incorrectly. The correct answer is $difference.</p>'n";
} 

if ($product == $guess) {
echo "<p>Congratulations $firstname. You answered correctly with $guess.<p>'n";
} else if ($product != $guess){
echo "<p>$firstname, you answered incorrectly. The correct answer is $product.</p>'n";
}       

if ($quotient == $guess) {
echo "<p>Congratulations $firstname. You answered correctly with $guess.<p>'n";
} else if ($quotient != $guess){
echo "<p>$firstname, you answered incorrectly. The correct answer is $quotient.</p>'n";
} 

} //end of the isset submit conditional statement

//show the form if it is the user's first time her OR if any of the required forms are missing
if(!isset($_POST ['submit']) OR empty($firstname) OR empty($num1) OR empty($num2)) { ?>
<h2>Please fill out the following: </h2>

<!--FORM BEGINS-->
<form action= "<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
<p><label for="firstname">Please enter your first name: </label>
<input id="firstname" type="text" size="30" name="firstname" value="<?php if(isset($firstname)) echo $firstname; ?>"/><p>
<!--Challenge Dealio-->
<p><label for="Num1">Please enter a number: </label>
<input id="Num1" type="number" size="30" name="num1" value="<?php if(isset($num1)) echo $num1; ?>" /></p>
<p><label for="Num2">Please enter another number: </label>
<input id="Num2" type="number" size="30" name="num2" value="<?php if(isset($num2)) echo $num2; ?>"/><p>
<p>Please choose one of the following: </p>
<p>
    <input name="add" id="answerswer" type="radio" value="add" />Add<br />
    <input name="subtract" id="answerswer" type="radio" value="subtract" />Subtract<br />
    <input name="multiply" id="answerswer" type="radio" value="multiply" />Multiply<br />
    <input name="divide" id="answerswer" type="radio" value="divide" />Divide<br />
</p>  
<p><label for="guess">Please put in a guess for the answer: </label>
<input id="guess" type="number" size="30" name="guess" value="<?php if(isset($guess)) echo $guess; ?>"/></p>
<p><label for="birthday">Please enter your birth date: </label>
<input id="birthday" type="date" size="30" name="birthday" value="<?php if(isset($birthday)) echo $birthday; ?>"/></p>
<!--Submit Button-->
<input type="submit" name="submit" value="Enter" />
</form>
<?php
} //end form conditional statement
?>

</body>
</html>


What did I do wrong? And how can I go about fixing this?

首先,所有的单选按钮应该有相同的名称和不同的值。同一页面中不能有相同的id

 <p>
     <input name="action" id="add" type="radio" value="add" />Add<br />
     <input name="action" id="subtract" type="radio" value="subtract" />Subtract<br />
     <input name="action" id="multiply" type="radio" value="multiply" />Multiply<br />
     <input name="action" id="divide" type="radio" value="divide" />Divide<br />
 </p>  

然后在你的php执行选中的选项,

 if($_POST['action'] == "add") {
     $result = $num1 + $num2;
 } else if($_POST['action'] == "subtract") {
     $result = $num1 - $num2;
 } else if($_POST['action'] == "multiply") {
     $result  = $num1 * $num2;
 } else if($_POST['action'] == "divide") {
     $result = $num1 / $num2;
 }

将所有值重命名为$result

 if($result == $guess) {
      echo "<p>Congratulations $firstname. You answered correctly with $guess.<p>'n";
 } else {
      echo "<p>$firstname, you answered incorrectly. The correct answer is $difference.</p>'n";
} 

不需要检查那么多次,将结果取为1个变量,只检查一次。

Edit:生日部分鉴于

<select name="year">add options here</select>
<select name="month">add options here</select>
<select name="day">add options here</select>
在PHP,

$month = $_POST['month'];
$year = $_POST['year'];
$day = $_POST['day'];
$date = $year ."-". $month ."-".$day;
$date = date("Y-m-d",strtotime($date));
if(date('m-d') == date('m-d', $date)) {
    // today is users birthday. show any message you want here.
 }

首先,你不能在收音机上使用相同的id。

<p>
   <input name="action" id="add" type="radio" value="add" />Add<br />
   <input name="action" id="subtract" type="radio" value="subtract" />Subtract<br />
   <input name="action" id="multiply" type="radio" value="multiply" />Multiply<br />
   <input name="action" id="divide" type="radio" value="divide" />Divide<br />
</p>  

那么您没有验证用户通过复选框选择的函数。您正在遍历所有ifelse,而没有过滤所选择的函数。

我要做的是使用Switch Case语句来筛选所选择的计算方法,然后比较猜测是否正确。比如:

switch $answer {
                case "add":
                //Check if guess is right and echo
                break;
                case "substract":
                //Check if guess is right and echo
                break;
                case "multiply":
                //Check if guess is right and echo
                break; 
                case "divide":
                //Check if guess is right and echo
                break;
              };

如果你不被允许使用Switch Case语句,那么你应该首先检查哪个答案被标记,然后如果猜测是正确的:

if($answer == "add"){
   if($sum == $guess){
      echo "Congrats";
   } else {
      echo "error";
   }
} else if($answer == "substract"){
   if($difference == $guess){
      echo "Congrats";
   } else {
      echo "error";
   }
} else if($answer == "multiply"){
   if($product == $guess){
      echo "Congrats";
   } else {
      echo "error";
   }
} else if($answer == "divide"){
   if($quotient == $guess){
      echo "Congrats";
   } else {
      echo "error";
   }
}

希望能有所帮助。