If isset $_POST
PhpIssetPhp Problem Overview
I have a form on one page that submits to another page. There, it checks if the input mail is filled. If so then do something and if it is not filled, do something else. I don't understand why it always says that it is set, even if I send an empty form. What is missing or wrong?
step2.php:
<form name="new user" method="post" action="step2_check.php">
<input type="text" name="mail"/> <br />
<input type="password" name="password"/><br />
<input type="submit" value="continue"/>
</form>
step2_check.php:
if (isset($_POST["mail"])) {
echo "Yes, mail is set";
} else {
echo "N0, mail is not set";
}
Php Solutions
Solution 1 - Php
Most form inputs are always set, even if not filled up, so you must check for the emptiness too.
Since !empty() is already checks for both, you can use this:
if (!empty($_POST["mail"])) {
echo "Yes, mail is set";
} else {
echo "No, mail is not set";
}
Solution 2 - Php
Use !empty instead of isset.
isset return true for $_POST because $_POST array is superglobal and always exists (set).
Or better use $_SERVER['REQUEST_METHOD'] == 'POST'
Solution 3 - Php
From php.net, isset
> Returns TRUE if var exists and has value other than NULL, FALSE > otherwise.
empty space is considered as set. You need to use empty() for checking all null options.
Solution 4 - Php
If you send the form empty, $_POST['mail'] will still be sent, but the value is empty. To check if the field is empty you need to check
if(isset($_POST["mail"]) && trim($_POST["mail"]) != "") { .. }
Solution 5 - Php
You can simply use:
if($_POST['username'] and $_POST['password']){
$username = $_POST['username'];
$password = $_POST['password'];
}
Alternatively, use empty()
if(!empty($_POST['username']) and !empty($_POST['password'])){
$username = $_POST['username'];
$password = $_POST['password'];
}
Solution 6 - Php
Add the following attribute to the input text form: required="required".
If the form is not filled, it will not allow the user to submit the form.
Your new code will be:
<form name="new user" method="post" action="step2_check.php">
<input type="text" name="mail" required="required"/> <br />
<input type="password" name="password" required="required"/><br />
<input type="submit" value="continue"/>
if (isset($_POST["mail"])) {
echo "Yes, mail is set";
}
Solution 7 - Php
Maybe you can try this one:
if (isset($_POST['mail']) && ($_POST['mail'] !=0)) { echo "Yes, mail is set"; } else { echo "No, mail is not set"; }
Solution 8 - Php
<?php
if(isset($_POST['mail']) && $_POST['mail']!='') {
echo "Yes, mail is set";
}else{
echo "N0, mail is not set";
}
?>
Solution 9 - Php
Lets Think this is your HTML Form in step2.php
> step2.php
<form name="new user" method="post" action="step2_check.php">
<input type="text" name="mail"/> <br />
<input type="password" name="password"/><br />
<input type="submit" value="continue"/>
</form>
I think you need it for your database, so you can assign your HTML Form Value to php Variable, now you can use Real Escape String and below must be your
> step2_check.php
if(isset($_POST['mail']) && !empty($_POST['mail']))
{
$mail = mysqli_real_escape_string($db, $_POST['mail']);
}
Where $db is your Database Connection.
Solution 10 - Php
Check to see if the FORM has been submitted first, then the field. You should also sanitize the field to prevent hackers.
form name="new user" method="post" action="step2_check.php">
<input type="text" name="mail"/> <br />
<input type="password" name="password"/><br />
<input type="submit" id="SubmitForm" name= "SubmitForm" value="continue"/>
</form>
step2_check:
if (isset($_POST["SubmitForm"]))
{
$Email = sanitize_text_field(stripslashes($_POST["SubmitForm"]));
if(!empty($Email))
echo "Yes, mail is set";
else
echo "N0, mail is not set";
}
}
Solution 11 - Php
To answer the posted question: isset and empty together gives three conditions. This can be used by Javascript with an ajax command as well.
$errMess="Didn't test"; // This message should not show
if(isset($_POST["foo"])){ // does it exist or not
$foo = $_POST["foo"]; // save $foo from POST made by HTTP request
if(empty($foo)){ // exist but it's null
$errMess="Empty"; // #1 Nothing in $foo it's emtpy
} else { // exist and has data
$errMess="None"; // #2 Something in $foo use it now
}
} else { // couldn't find ?foo=dataHere
$errMess="Missing"; // #3 There's no foo in request data
}
echo "Was there a problem: ".$errMess."!";
Solution 12 - Php
You can try this:
if (isset($_POST["mail"]) !== false) {
echo "Yes, mail is set";
}else{
echo "N0, mail is not set";
}
Solution 13 - Php
<form name="new user" method="post" action="step2_check.php">
<input type="text" name="mail" required="required"/> <br />
<input type="password" name="password" required="required"/><br />
<input type="submit" value="continue"/>
</form>
<?php
if (!empty($_POST["mail"])) {
echo "Yes, mail is set";
}else{
echo "N0, mail is not set";
}
?>
Solution 14 - Php
You can try,
<?php
if (isset($_POST["mail"])) {
echo "Yes, mail is set";
}else{
echo "N0, mail is not set";
}
?>
Solution 15 - Php
$-POST METHOD: if we use POST method in the form tag to pass data,we can find data in the server using $_POST array.using this array name we fetch data from server.($_POST['name'])Information sent from a form with the POST method is invisible to others(all names/values are embedded within the body of the HTTP request) and has no limits n the amount of information to send. Example Code:
<html>
<head>
</head>
<body>
<?php
if(isset($_POST['submit']))
{if(isset($_POST['name']) && isset($_POST['roll']))
{echo"<h1>form submitted</h1>";echo"your name is". $_POST['name']."<br>";
echo "your roll number is". $_POST['roll']."<br>";}}
else{?>
<form action="" method="POST">
Name:<input type="text" name="name"><br><br>
Roll:<input type="text" name="roll"><br>
<br><input type="submit" value="submit" name="submit">
</form>
<?php}?>
</body>
</html>