简单的 PHP 计算器
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Simple PHP calculator
提问by user2953989
I'm creating a basic PHP calculator that lets you enter two values and chose your operator then displays the answer. Everything is working fine except it's not outputting the answer to the browser.
我正在创建一个基本的 PHP 计算器，它允许您输入两个值并选择您的运算符，然后显示答案。除了不向浏览器输出答案外，一切正常。
Here are the codes for my html and PHP files:
这是我的 html 和 PHP 文件的代码：
<head>
<meta charset="utf-8">
<title>Calculator</title>
</head>
<body>
<form method="post" attribute="post" action="disp_form.php">
<p>First Value:<br/>
<input type="text" id="first" name="first"></p>
<p>Second Value:<br/>
<input type="text" id="second" name="second"></p>
<input type="radio" name="group1" id="add" value="add" checked="true"><p>+</p><br/>
<input type="radio" name="group1" id="subtract" value="subtract"><p>-</p><br/>
<input type="radio" name="group1" id="times" value="times"><p>x</p><br/>
<input type="radio" name="group1" id="divide" value="divide"><p>/</p><br/>
<p></p>
<button type="submit" name="answer" id="answer" value="answer">Calculate</button>
</form>
</body>
</html>
PHP file:
PHP文件：
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Answer</title>
</head>
<body>
<p>The answer is:
<?php
if($_POST['group1'] == add) {
echo "$first + $second";
}
else if($_POST['group1'] == subtract) {
echo "$first - $second";
}
else if($_POST['group1'] == times) {
echo "$first * $second";
}
else($_POST['group1'] == divide) {
echo "$first / $second";
}
?>
</p>
</body>
</html>
回答by Naseem Ahmad
<?php
$result = "";
class calculator
{
var $a;
var $b;
function checkopration($oprator)
{
switch($oprator)
{
case '+':
return $this->a + $this->b;
break;
case '-':
return $this->a - $this->b;
break;
case '*':
return $this->a * $this->b;
break;
case '/':
return $this->a / $this->b;
break;
default:
return "Sorry No command found";
}
}
function getresult($a, $b, $c)
{
$this->a = $a;
$this->b = $b;
return $this->checkopration($c);
}
}
$cal = new calculator();
if(isset($_POST['submit']))
{
$result = $cal->getresult($_POST['n1'],$_POST['n2'],$_POST['op']);
}
?>
<form method="post">
<table align="center">
<tr>
<td><strong><?php echo $result; ?><strong></td>
</tr>
<tr>
<td>Enter 1st Number</td>
<td><input type="text" name="n1"></td>
</tr>
<tr>
<td>Enter 2nd Number</td>
<td><input type="text" name="n2"></td>
</tr>
<tr>
<td>Select Oprator</td>
<td><select name="op">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select></td>
</tr>
<tr>
<td></td>
<td><input type="submit" name="submit" value=" = "></td>
</tr>
</table>
</form>
回答by KyleMassacre
Personally I would do a switch instead of all this if, else if, else
就个人而言，我会做一个 switch 而不是所有这些 if, else if, else
$first = $_POST['first'] + 0;//a small "hack" to make sure its an int but allow negs!!
$second= $_POST['second'] + 0;
$operator = $_POST["group1"];
switch($operator)
{
case "add"
echo "Answer is: " .$first + $second;
break;
case "subtract"
echo "Answer is: " .$first - $second;
break;
case "times"
echo "Answer is: " .$first * $second;
break;
case "divide"
echo "Answer is: " .$first / $second;
break;
}
回答by Daniel N
You also need to put the [== 'add'] math operation into quotes
您还需要将 [== 'add'] 数学运算放入引号中
if($_POST['group1'] == 'add') {
echo $first + $second;
}
complete code schould look like that :
完整的代码应该是这样的：
<?php
$first = $_POST['first'];
$second= $_POST['second'];
if($_POST['group1'] == 'add') {
echo $first + $second;
}
else if($_POST['group1'] == 'subtract') {
echo $first - $second;
}
else if($_POST['group1'] == 'times') {
echo $first * $second;
}
else if($_POST['group1'] == 'divide') {
echo $first / $second;
}
?>
回答by Chizzle
You need to assign $first and $second
您需要分配 $first 和 $second
$first = $_POST['first'];
$second= $_POST['second'];
Also, As Travesty3 said, you need to do your arithmetic outside of the quotes:
另外，正如 Travesty3 所说，您需要在引号之外进行算术运算：
echo $first + $second;
回答by BlackHatSamurai
You need to get the values the same way to get the calculator operation which looks like:
您需要以相同的方式获取值以获得如下所示的计算器操作：
<?php
if($_POST['group1'] == add) {
echo "$_POST['first']+ $_POST['second'];
}
... and so on
?>
Or, to make it easier, just do:
或者，为了更容易，只需执行以下操作：
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Answer</title>
</head>
<body>
<p>The answer is:
<?php
$first = $_POST['first'];
$second= $_POST['second'];
if($_POST['group1'] == add) {
echo "$first + $second";
}
else if($_POST['group1'] == subtract) {
echo "$first - $second";
}
else if($_POST['group1'] == times) {
echo "$first * $second";
}
else($_POST['group1'] == divide) {
echo "$first / $second";
}
?>
</p>
</body>
</html>
回答by mellowfish
$first = doubleval($_POST['first']);
$second = doubleval($_POST['second']);
if($_POST['group1'] == 'add') {
echo "$first + $second = ".($first + $second);
}
// etc
回答by SagarPPanchal
Check string using single quotes
使用单引号检查字符串
Ex. $_POST['group1'] == 'add'
前任。 $_POST['group1'] == 'add'
回答by Murtaza JAFARI
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Calculator</title>
</head>
<body>
HTML Code is here:
<form method="post">
<input type="text" name="numb1">
<input type="text" name="numb2">
<select name="operator" id="">
<option>None</option>
<option>Add</option>
<option>Subtract</option>
<option>Multiply</option>
<option>Divide</option>
<option>Square</option>
</select>
<button type="submit" name="submit" value="submit">Calculate</button>
</form>
PHP Code:
<?php
if (isset($_POST['submit'])) {
$result1 = $_POST['numb1'];
$result2 = $_POST['numb2'];
$operator = $_POST['operator'];
switch ($operator) {
case 'None':
echo "You need to select any operator";
break;
case 'Add':
echo $result1 + $result2;
break;
case 'Subtract':
echo $result1 - $result2;
break;
case 'Multiply':
echo $result1 * $result2;
break;
case 'Divide':
echo $result1 / $result2;
break;
case 'Square':
echo $result1 ** $result2;
break;
}
}
?>
enter code here
</body>
</html>
回答by Adit Doshi
Make this changes in php file
在 php 文件中进行此更改
<html>
<head>
<meta charset="utf-8">
<title>Answer</title>
</head>
<body>
<p>The answer is:
<?php
$first = $_POST['first'];
$second= $_POST['second'];
if($_POST['group1'] == 'add') {
echo $first + $second;
}
else if($_POST['group1'] == 'subtract') {
echo $first - $second;
}
else if($_POST['group1'] == 'times') {
echo $first * $second;
}
else if($_POST['group1'] == 'divide') {
echo $first / $second;
}
else {
echo "Enter the numbers properly";
}
?>
</p>
</body>
</html>
