How to check if form field is empty using PHP

Question

I am trying to check if the field is empty. If it is, redirect to sign uppage. Right now, it just keeps on creating multiple account with NULL username and password. I tried using strlen(), but it doesn't seem to be working.

<?php
        try{
        $username = trim($_POST['username']);
        $password = trim($_POST['password']);
        $hash = crypt($password_signup, '$3a$08$2'); // salt 

        $connection = new PDO ('mysql:host=localhost;dbname=tongue', 'web', 'lapming1');
        $connection -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $connection -> setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

        require_once("functions.php");

        $sql = 'SELECT email, hash FROM user WHERE email=:username';
        $row = login ($sql, $connection, $username_signup);

        if ($username = false){
            header("Location: sign_up.php?error");
        };

        if ($row) {
            header("Location: sign_up.php?msg=1");
        }
        else {
            $sql = 'INSERT INTO user(email, hash) VALUES (:username, :password)';
            create($sql, $connection, $username_signup, $password_signup);
            header("Location: index.php");
        };


    $connection = null;

    } catch(PDOException $e) {
        echo $e->getMessage();
    }

?>

Can any one tell me why this guy got a -1 ??? If he knows the answer he would not be asking .. am sure some of us once had similar issues in the past ..... — Baba
– Baba, Commented Mar 23, 2012 at 8:14

Baba · Accepted Answer · 2012-03-23 08:08:54Z

2

I can see the error .. you are using basic assignment operator "=" insted of Comparison operators "=="

Change

   if ($username = false){
        header("Location: sign_up.php?error");
    };

To

   if ($username == false){
        header("Location: sign_up.php?error");
    };

Or Better Approach

  if (empty($username){
        header("Location: sign_up.php?error");
    };

Thanks :)

edited Mar 23, 2012 at 8:08

answered Mar 23, 2012 at 8:06

Baba

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1 Comment

Brian Cherdak Over a year ago

You missed a parenthesis ending on the last one.

Sudhir Bastakoti · Accepted Answer · 2012-03-23 08:07:00Z

2


$username = trim($_POST['username']);
if(!empty($username)) {
   ....is not empty
}

answered Mar 23, 2012 at 8:07

Sudhir Bastakoti

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Comments

Starx · Accepted Answer · 2012-03-23 08:08:08Z

0

Its easier this way

if (!strlen($username)){
 header("Location: sign_up.php?error");
};

And you are not using correct comparison operators

$username = false assigns the boolean value false to $username and will always be returned as true, and thus the header will keep on being sent.

answered Mar 23, 2012 at 8:08

Starx

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