Can't access form variable with php - php

Question

I'm new to Web development and have been messing around with BootStrap. I've been trying to make a Web form on my new website, but I can't seem to access the username variable.
Here's my form code:
<form class="navbar-form navbar-left" role="search" action="username">
<div class="form-group">
<input name="username" type="text" class="form-control" placeholder="Username">
</div>
<button type="submit" class="btn btn-default">Search</button>
</form>
And here's my index.php in the username folder:
<?php
echo $_POST['username'];
echo 'fail';
echo 'username';
if(isset($_POST['username'])) {
$name = $_POST['username'];
echo 'success';
}
?>
With my debugging, I get the message fail to show up, but not the username, so I assume I am doing something wrong either with setting the username, or accessing it.

Answer 1

According to your description, your HTML code should look something like this:
<form method="post" class="navbar-form navbar-left" role="search" action="username/index.php">
<div class="form-group">
<input name="username" type="text" class="form-control" placeholder="Username">
</div>
<button type="submit" class="btn btn-default">Search</button>
</form>
You could also use <input class="btn btn-default" type="submit" value="Search"/> instead of <button type="submit"></button>.

Answer 2

You have the following mistakes
You didn't set the method attribute in your form.So when the form is submitted the data will be posted via get method.And you need to access $_GET variable for getting the form data. So here when you submit the form the data will be in $_GET variable.But you are trying to access $_POST variable in your code.So you can try like setting the method attribute to method="post in your form and continue with the same code in index.php or try changing $_POST to $_GET` in your index.php and making no changes in your form
You are definging the code in index.php when the form is submitted.So you need to set the action="index.php" in your form
So it will be like this finally
<form class="navbar-form navbar-left" role="search" action="username/index.php" method="post">
<div class="form-group">
<input name="username" type="text" class="form-control" placeholder="Username">
</div>
<button type="submit" class="btn btn-default">Search</button>
</form>
index.php
<?php
echo $_POST['username'];
echo 'fail';
echo 'username';
if(isset($_POST['username'])) {
$name = $_POST['username'];
echo 'success';
}
?>
OR
<form class="navbar-form navbar-left" role="search" action="username/index.php">
<div class="form-group">
<input name="username" type="text" class="form-control" placeholder="Username">
</div>
<button type="submit" class="btn btn-default">Search</button>
</form>
index.php
<?php
echo $_GET['username'];
echo 'fail';
echo 'username';
if(isset($_GET['username'])) {
$name = $_GET['username'];
echo 'success';
}
?>

Answer 3

Set your action attribute to index.php and set your method="post" if you access the username with $_POST['username'].