The code will not produce a calculated result for me.. can anyone help me?
The HTML displays properly, I can input the constants, they are updated in the URL. The PHP GET function seems to be working but not producing any results on the page.
<form>
<input type="text" name="num1" placeholder="Constant">
<input type="text" name="num2" placeholder="Constant">
<select name="Operator">
<option>Select Option</option>
<option>Add</option>
<option>Subtract</option>
<option>Multiply</option>
<option>Divide</option>
</select>
<br>
<br>
<button type="Submit" name="Submit" value="Submit">Calculate</button>
</form>
<p>The answer is: </p>
if (isset($_GET['Submit'])) {
$result1 = $_GET['num1'];
$result2 = $_GET['num2'];
$operator = $_GET['Operator'];
switch ($operator) {
case 'Select Option':
echo "Error";
break;
case 'Add':
echo $result1 + $result2;
break;
case 'Subtract':
echo $result1 - $result2;
break;
case 'Multiply':
echo $result1 * $result2;
break;
case 'Divide':
echo $result1 / $result2;
break;
}}
Related
This is the code that I'm using. All the arithemetic operations are done successfully except subtraction. When Subtraction is selected, it gives the error. If I use two different echo statements, one for "The answer is: " and the other echo statement for the subtraction between two variables, it gives no error. What is the reason behind the generation of this error when both the variables string are printed using one echo statement??
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Calculator</title>
</head>
<body>
<form>
<input type="text" name="num1" placeholder="First Number">
<input type="text" name="num2" placeholder="Second Number">
<select name="operator">
<option>None</option>
<option>Add</option>
<option>Subtract</option>
<option>Multiply</option>
<option>Divide</option>
</select>
<br>
<button name="submit" value="submit">Calculate</button>
</form>
<?php
if (isset($_GET['submit'])) {
$num1 = $_GET['num1'];
$num2 = $_GET['num2'];
$operator = $_GET['operator'];
switch ($operator) {
case "None":
echo "You need to set a method!";
break;
case 'Add':
echo "The answer is: ".$num1 + $num2;
break;
case 'Subtract':
echo "The answer is: ".$num1 - $num2;
break;
case 'Multiply':
echo "The answer is: ".$num1 * $num2;
break;
case 'Divide':
echo "The answer is: ".$num1 / $num2;
break;
}
}
?>
</body>
</html>
https://www.php.net/manual/en/language.operators.precedence.php
The . in your string concatenation has a higher operator precedence than your -. You should add parentheses around your $num expressions.
switch ($operator) {
case "None":
echo "You need to set a method!";
break;
case 'Add':
echo "The answer is: ".($num1 + $num2);
break;
case 'Subtract':
echo "The answer is: ". ($num1 - $num2);
break;
case 'Multiply':
echo "The answer is: ".($num1 * $num2);
break;
case 'Divide':
echo "The answer is: ".($num1 / $num2);
break;
}
Here is my form
<form>
<input type="text" name="num1" placeholder="Digets">
<input type="text" name="num2" placeholder="Digets">
<select name="operator">
<option>Add</option>
<option>Subtract</option>
<option>Multiply</option>
<option>Divide</option>
</select>
<button type="submit" value="submit" name="submit">Check for the answer</button>
<p>Your answer is : </p>
</form>
<?php
if (isset($_GET['$submit'])){
$result1 = $_GET['$num1'];
$result2 = $_GET['$num2'];
$operator = $_GET['$operator'];
switch ('$operator'){
case "Add":
echo $result1 + $result2;
break;
case "Subtract":
echo $result1 - $result2;
break;
case "Multiply":
echo $result1 * $result2;
break;
case "Divide":
echo $result1 / $result2;
break;
}
}
?>
When i click on the calculate button I don't see an answer and i tried fixing all my bugs but it seems to me as if their is something wrong with the switch.
Try this:-
you are making some mistake while getting values and switch parameter.
like you are geetting value $_GET['$num1'] instead you need to use $_GET['num1']
as you just need to pass variable switch ($operator) instead switch ('$operator') of quotation mark.
<?php
if (isset($_GET['submit'])){
$result1 = $_GET['num1'];
$result2 = $_GET['num2'];
$operator = $_GET['operator'];
switch ($operator){
case 'Add':
$FResult =$result1 + $result2;
echo "Result:"+ $FResult ;
break;
case 'Subtract':
$FResult =$result1 - $result2;
echo "Result:"+ $FResult ;
break;
case 'Multiply':
$FResult =$result1 * $result2;
echo "Result:"+ $FResult ;
break;
case 'Divide':
$FResult =$result1 / $result2;
echo "Result:"+ $FResult ;
break;
default :
echo "wrong";
}
}
?>
The mistake you have made:
1). You are passing variable directly into get element i.e, it should be like $_GET['submit'] instead of $_GET['$submit'];
2). You are passing string instead of variable i.e, switch ('$operator') should be switch ($operator)
check it out where you have made mistake
<form method="GET" action="">
<input type="text" name="num1" placeholder="Digets">
<input type="text" name="num2" placeholder="Digets">
<select name="operator">
<option>Add</option>
<option>Subtract</option>
<option>Multiply</option>
<option>Divide</option>
</select>
<button type="submit" value="submit" name="submit">Check for the answer</button>
<p>Your answer is : </p>
</form>
<?php
if (isset($_GET['submit'])){
$result1 = $_GET['num1'];
$result2 = $_GET['num2'];
$operator = $_GET['operator'];
switch ($operator){
case "Add":
echo $result1 + $result2;
break;
case "Subtract":
echo $result1 - $result2;
break;
case "Multiply":
echo $result1 * $result2;
break;
case "Divide":
echo $result1 / $result2;
break;
}
}
?>
You were looking for PHP solution, here is one:-
<?php
if (isset($_POST['submit'])){
$result1 = $_POST['num1'];
$result2 = $_POST['num2'];
$operator = $_POST['operator'];
switch($operator){
case "Add":
$res = +$result1 + +$result2;
break;
case "Subtract":
$res = +$result1 - +$result2;
break;
case "Multiply":
$res = +$result1 * +$result2;
break;
case "Divide":
$res = +$result1 / +$result2;
break;
}
}
?>
<form method="post" action="">
<input type="text" name="num1" id="num1" placeholder="Digets">
<input type="text" name="num2" id="num2" placeholder="Digets">
<select name="operator" id="operator">
<option value="Add">Add</option>
<option value="Subtract">Subtract</option>
<option value="Multiply">Multiply</option>
<option value="Divide">Divide</option>
</select>
<input type="submit" name="submit" id="submit" value="Calculate" />
<p>Your answer is : <input name="res" value="<?php echo $res; ?>"></p>
</form>
This is what you were looking for .
<form>
<input type="number" name="num1" placeholder="Digets">
<input type="number" name="num2" placeholder="Digets">
<select name="operator">
<option value="+">Add</option>
<option value="-">Subtract</option>
<option value="*">Multiply</option>
<option value="/">Divide</option>
</select>
<button type="submit" value="submit" name="submit">Check for the answer</button>
<p>Your answer is : </p>
</form>
<?php
if (isset($_REQUEST['submit'])){
$result1 = $_REQUEST['num1'];
$result2 = $_REQUEST['num2'];
$operator = $_REQUEST['operator'];
$res = $result1.$operator.$result2;
$p = eval('return '.$res.';');
print $p;
}
?>
<form>
<input type="number" name="num1" placeholder="Digets">
<input type="number" name="num2" placeholder="Digets">
<select name="operator">
<option>Add</option>
<option>Subtract</option>
<option>Multiply</option>
<option>Divide</option>
</select>
<button type="submit" value="submit" name="submit">Check for the answer</button>
<p>Your answer is : </p>
</form>
<?php
if (isset($_REQUEST['submit'])){
$result1 = $_REQUEST['num1'];
$result2 = $_REQUEST['num2'];
$operator = $_REQUEST['operator'];
switch ($operator){
case "Add":
echo $result1 + $result2;
break;
case "Subtract":
echo $result1 - $result2;
break;
case "Multiply":
echo $result1 * $result2;
break;
case "Divide":
echo $result1 / $result2;
break;
}
}
?>
Another way:
<form>
<input type="number" name="num1" placeholder="Digets">
<input type="number" name="num2" placeholder="Digets">
<select name="operator">
<option value="+">Add</option>
<option value="-">Subtract</option>
<option value="*">Multiply</option>
<option value="/">Divide</option>
</select>
<button type="submit" value="submit" name="submit">Check for the answer</button>
<p>Your answer is : </p>
</form>
<?php
if (isset($_REQUEST['submit'])){
$result1 = $_REQUEST['num1'];
$result2 = $_REQUEST['num2'];
$operator = $_REQUEST['operator'];
$res = $result1.$operator.$result2;
$p = eval('return '.$res.';');
print $p;
}
?>
You should set option value in select tag (operator which you want for calculator) <option value="">.
change you input type="text" into type="number"
<form method="GET">
<input type="number" name="num1">
<input type="number" name="num2">
<select name="operator">
<option value='+'>Add</option>
<option value='-'>Subtract</option>
<option value='*'>Multiply</option>
<option value='/'>Divide</option>
</select>
<button type="submit" value="submit" name="submit">calculate</button>
<p>Answer :</p>
</form>
<?php
if (isset($_GET['submit'])){
$num1 = $_GET['num1'];
$num2 = $_GET['num2'];
$operator = $_GET['operator'];
switch ($operator){
case "+":
echo $num1 + $num2;
break;
case "-":
echo $num1 - $num2;
break;
case "*":
echo $num1 * $num2;
break;
case "/":
echo $num1 / $num2;
break;
}
}
?>
what you have done is that you are calculating it in the back-end and the form is refreshing the page , but not displaying the result anywhere on the page . Its better to do with a JQuery so that result will come instantly without page refresh . Just check the code below:-
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
<script>
$(document).ready(function(){
$("#submit").on('click', function(){
var num1 = $("#num1").val() ;
var num2 = $("#num2").val() ;
var operator = $("#operator").val() ;
var result = 0 ;
switch(operator){
case "Add":
result = +num1 + +num2 ;
document.getElementById("res").innerHTML = result ;
break ;
case "Subtract":
result = +num1 - +num2 ;
document.getElementById("res").innerHTML = result ;
break ;
case "Multiply":
result = +num1 * +num2 ;
document.getElementById("res").innerHTML = result ;
break ;
case "Divide":
result = +num1 / +num2 ;
document.getElementById("res").innerHTML = result ;
break ;
}
});
});
</script>
<div>
<input type="text" name="num1" id="num1" placeholder="Digets">
<input type="text" name="num2" id="num2" placeholder="Digets">
<select name="operator" id="operator">
<option value="Add">Add</option>
<option value="Subtract">Subtract</option>
<option value="Multiply">Multiply</option>
<option value="Divide">Divide</option>
</select>
<button name="submit" id="submit">Check for the answer</button>
<p>Your answer is : <span id="res"></span></p>
</div>
This is running successfully .
I want to display results of the calculation at the end of the program as a list. After each post, the result is added to the list of previous results.
Simply, I want to display a history of the result of the calculations done.
<form method="post" >
<p>A:<input value="<?php echo $_POST['num1']?>" min="0" max="1000" type="number" name="num1"></p>
<p>B:<input value="<?php echo $_POST['num2']?>" min="0" max="1000" type="number" name="num2"></p>
<p>
<select name="op">
<option value="jaam">+</option>
<option value="zarb">*</option>
<option value="taghtsim">/</option>
<option value="tafrigh">-</option>
</select>
</p>
<input type="submit" name="">
<hr>
</form>
<?php
if (isset($_POST['num1']) && isset($_POST['num2']) && isset($_POST['op']))
{
switch ($_POST['op'])
{
case 'jaam':
$r = $_POST['num1'] + $_POST['num2'];
break;
case 'zarb':
$r = $_POST['num1'] * $_POST['num2'];
break;
case 'taghtsim':
$r = $_POST['num1'] / $_POST['num2'];
break;
case 'tafrigh':
$r = $_POST['num1'] - $_POST['num2'];
break;
default:
$r = "Error!";
break;
}
}
?>
The code:
<!DOCTYPE html>
<html>
<head>
<title>Greeting Service!</title>
</head>
<body>
<center>
<form method="post" action="">
<h1>What's Your Name?</h1>
<input type="text" name="name" placeholder="Name Here" />
<h4>Greet me in:
<select name="language">
<option value="option1">English</option>
<option value="option2">Chinese</option>
<option value="option3">French</option>
</select>
</h4>
<input type="submit" value="Greet Me!" />
<?php
if (isset($_POST['language'])) {
switch ($language) {
case "option1":
$result = "Hello, $name!";
break;
case "option2":
$result = "你好, $name!";
break;
case "option3":
$result = "Bonjour, $name!";
break;
}
}
?>
</form>
</center>
</body>
</html>
I'm not sure why it doesn't display the name i enter in from the input text box with the greeting according to each different language. I have used $_POST to submit the form and used a switch and case in my php code. Can someone help me out, i would like the name that is entered in the textbox to display when i have chosen which language i want the greeting to come out with. Thanks.
You don't have $language defined. What you should use is $_POST['language'] :
if (isset($_POST['language'])) {
switch ($_POST['language']) {
EDIT: didn't notice the $name variable as said by Meenesh Jain.
And the last thing: you never do anything with the result. Not sure if that's intended or not, but I would add an echo $result; at the end.
This is happening because you are not initializing any value to $language
just place code like $language = $_POST['language'];
above the switch statement.
declare a varibale $name and assign $_POST['name'] to it
<!DOCTYPE html>
<html>
<head>
<title>Greeting Service!</title>
</head>
<body>
<center>
<form method="post" action="">
<h1>What's Your Name?</h1>
<input type="text" name="name" placeholder="Name Here" />
<h4>Greet me in:
<select name="language">
<option value="option1">English</option>
<option value="option2">Chinese</option>
<option value="option3">French</option>
</select>
</h4>
<input type="submit" value="Greet Me!" />
<?php
if (isset($_POST['language'])) {
$name = $_POST['name'];
switch ($language) {
case "option1":
$result = "Hello, $name!";
break;
case "option2":
$result = "你好, $name!";
break;
case "option3":
$result = "Bonjour, $name!";
break;
}
}
?>
</form>
</center>
</body>
</html>
$name is not defined
change your code like this
if (isset($_POST['language'])) {
switch ($_POST['language']) {
case "option1":
$result = "Hello, {$_POST['name']}!";
break;
case "option2":
$result = "你好, {$_POST['name']}!";
break;
case "option3":
$result = "Bonjour, {$_POST['name']}!";
break;
}
}
?>
tried using php to solve your question but could not get it through but Javascript does it seamlessly. Tested though. Find code below
<center>
<form method="post" action="index.php">
<h1>What's Your Name?</h1>
<input type="text" name="myName" placeholder="Name Here" id="myName"/>
<h4>Greet me in:
<select name="lang" onchange="getValue()" id="language">
<option value="English">English</option>
<option value="Chinese">Chinese</option>
<option value="French">French</option>
</select>
</h4>
<input type="submit" value="Greet Me!" />
<div id="show"></div>
<script type="text/javascript">
function getValue(){
var myName = document.getElementById("myName").value;
var lang = document.getElementById("language").value;
if(myName == null){
document.getElementById("show").innerHTML = "No name selected";
}
else{
switch(lang) {
case 'English':
document.getElementById("show").innerHTML = "Hello" + ' ' + myName;
break;
case 'Chinese':
document.getElementById("show").innerHTML = "你好" + ' ' + myName;
break;
case 'French':
document.getElementById("show").innerHTML = "Bonjour" + ' ' + myName;
break;
}
}
}
</script>
Copied the code and replace it where you have same.
Glad i could help.
I've recently started the assignment of building a calculator out of PHP and I can't seem to find what I'm doing wrong in my code. Every time I press calculate it doesn't give me back my solution.
<?php
$num1 = $_GET['num1'];
$num2 = $_GET['num2'];
$cal = $_GET['opt'];
if($num2, $num2 != (int)){
$num1=0;
$num2=0;
}
switch($cal) {
case 'add':
echo $num1+$num2;
break;
case 'sub':
echo $num1-$num2;
break;
case 'mul':
echo $num1*$num2;
break;
case 'div':
echo $num1/$num2;
break;
default:
echo "Invalid Operator";
}
?>
Here is the HTML
<form action="calculate.php" method="GET"/>
Number 1:<input type="text" name="num1"/>
<br />
<select>
<option type="text" name="opt" value="add"> + </option>
<option type="text" name="opt" value="sub"> - </option>
<option type="text" name="opt" value="mul"> * </option>
<option type="text" name="opt" value="div"> / </option>
</select>
<br />
Number 2:<input type="text" name="num2"/>
<br />
<input type="submit" value="calculate"/>
</form>
if($num2, $num2 != (int)) looks like a syntax error to me (the comma).
You just say it doesn't work, are you getting an error message? Have you made sure error reporting is on and displaying errors to your browser? I think it should tell you about the syntax error.
try :
$num1 = intval($_GET['num1']);
$num2 = intval($_GET['num2']);
and remove
if($num2, $num2 != (int)){
$num1=0;
$num2=0;
}
I would initialise the var differently:
<?php
$num1 = $num2 = 0;
if (isset($_GET['num1']) && isset($_GET['num1']) && isset($_GET['num1']))
{
$num1 = $_GET['num1'];
$num2 = $_GET['num2'];
// edit: added validation
if (!is_numeric($num1) || !is_numeric($num2))
{
$res = NULL;
}
else
{
$cal = $_GET['opt'];
switch($cal)
{
case 'add':
$res = $num1+$num2;
break;
case 'sub':
$res = $num1-$num2;
break;
case 'mul':
$res = $num1*$num2;
break;
case 'div':
$res = $num1/$num2;
break;
default:
$res = NULL;
}
}
}
// display html on the same file
?>
<html>
<body>
<form action="calculate.php" method="GET"/>
Number 1:<input type="text" name="num1"/>
<br />
<select>
<option type="text" name="opt" value="add"> + </option>
<option type="text" name="opt" value="sub"> - </option>
<option type="text" name="opt" value="mul"> * </option>
<option type="text" name="opt" value="div"> / </option>
</select>
<br />
Number 2:<input type="text" name="num2"/>
<br />
<input type="submit" value="calculate"/>
</form>
<? if (isset($res) && $res != NULL): ?>
<span class="result-label">Result:</span> <span class="result"><?=$res?></span>
<? endif ?>
</body>
</html>
This is wrong
if($num2, $num2 != (int)){
$num1=0;
$num2=0;
}
try
$num1 = intval( $num1 );
$num2 = intval( $num2 );