PHP Form Handling (original) (raw)
Last Updated : 14 Apr, 2025
Form handling is the process of collecting and processing information that users submit through HTML forms. In PHP, we use special tools called POSTand_POST and POSTand_GET to gather the data from the form. Which tool to use depends on how the form sends the data—either through the POST method (more secure, hidden in the background) or the GET method (data is visible in the URL).
- **Collecting Data: Retrieving form data using PHP.
- **Validating Data: Ensuring that the input meets expected formats.
- **Sanitizing Data: Cleaning up the data to prevent malicious content.
- **Processing Data: Using the data for its intended purpose (e.g., saving to a database, sending an email, etc.).
- **Returning a Response: Displaying feedback to the user or redirecting them to another page.
**Form Attributes
- **action: The action attribute specifies the URL where the form data will be sent when the form is submitted.
- **method: The method attribute specifies the HTTP method (GET or POST) to use when sending form data.
**name: The name attribute is crucial in PHP form handling, as it is used to refer to the data submitted by the form fields. username=username = username=_POST['username']; // Accessing the form data
**target: The target attribute specifies where to display the response after submitting the form. It determines where the resulting page (or response) will appear once the form is submitted.
- **enctype: The enctype (encoding type) attribute defines how the form data should be encoded when submitted to the server. This is particularly important when submitting forms that include file uploads.
**Form Elements
Form processing contains a set of controls through which the client and server can communicate and share information. The controls used in forms are:
- **Input Field: Input field is the most common form element, allowing users to input a single line of text, such as their name, address, or any other simple text information.
- **Password Input Field: The password input field hides the text entered, making it suitable for secure data entry like passwords.
- **Checkboxes: Checkboxes allow users to select multiple options from a set of choices. They are often used for lists of features or permissions.
Subscribe to newsletter
- **Radio Buttons: Radio buttons allow the user to choose only one option from a set of predefined options. This is useful for binary choices, such as gender selection.
Female
Male
- **Textarea: The textarea element allows users to input multiple lines of text, making it useful for longer messages, feedback, or comments.
**Creating a Simple Form
html `
">| Full Name: | |
| Email Address: | |
| Age: | |
| Feedback: | |
| Gender: | Female Male |
<?php
<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>u</mi><mi>l</mi><mi>l</mi><mi>n</mi><mi>a</mi><mi>m</mi><mi>e</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">fullname = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">u</span><span class="mord mathnormal" style="margin-right:0.01968em;">ll</span><span class="mord mathnormal">nam</span><span class="mord mathnormal">e</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>user_email = <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mi>s</mi><mi>e</mi><msub><mi>r</mi><mi>g</mi></msub><mi>e</mi><mi>n</mi><mi>d</mi><mi>e</mi><mi>r</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">user_gender = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9805em;vertical-align:-0.2861em;"></span><span class="mord mathnormal">u</span><span class="mord mathnormal">se</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span></span></span></span><span class="vlist-s"></span></span><span class="vlist-r"><span class="vlist" style="height:0.2861em;"><span></span></span></span></span></span></span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>user_feedback = $user_age = "";
// Check if the form was submitted
if ($_SERVER["REQUEST_METHOD"] == "POST") {
// Only process the POST data if the form is submitted
if (isset($_POST['fullname'])) {
<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>u</mi><mi>l</mi><mi>l</mi><mi>n</mi><mi>a</mi><mi>m</mi><mi>e</mi><mo>=</mo><mi>h</mi><mi>t</mi><mi>m</mi><mi>l</mi><mi>s</mi><mi>p</mi><mi>e</mi><mi>c</mi><mi>i</mi><mi>a</mi><mi>l</mi><mi>c</mi><mi>h</mi><mi>a</mi><mi>r</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">fullname = htmlspecialchars(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">u</span><span class="mord mathnormal" style="margin-right:0.01968em;">ll</span><span class="mord mathnormal">nam</span><span class="mord mathnormal">e</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">h</span><span class="mord mathnormal">t</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">s</span><span class="mord mathnormal">p</span><span class="mord mathnormal">ec</span><span class="mord mathnormal">ia</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">c</span><span class="mord mathnormal">ha</span><span class="mord mathnormal">rs</span><span class="mopen">(</span></span></span></span>_POST['fullname']);
}
if (isset($_POST['user_email'])) {
<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mi>s</mi><mi>e</mi><msub><mi>r</mi><mi>e</mi></msub><mi>m</mi><mi>a</mi><mi>i</mi><mi>l</mi><mo>=</mo><mi>h</mi><mi>t</mi><mi>m</mi><mi>l</mi><mi>s</mi><mi>p</mi><mi>e</mi><mi>c</mi><mi>i</mi><mi>a</mi><mi>l</mi><mi>c</mi><mi>h</mi><mi>a</mi><mi>r</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">user_email = htmlspecialchars(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8444em;vertical-align:-0.15em;"></span><span class="mord mathnormal">u</span><span class="mord mathnormal">se</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">e</span></span></span></span><span class="vlist-s"></span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal">mai</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">h</span><span class="mord mathnormal">t</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">s</span><span class="mord mathnormal">p</span><span class="mord mathnormal">ec</span><span class="mord mathnormal">ia</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">c</span><span class="mord mathnormal">ha</span><span class="mord mathnormal">rs</span><span class="mopen">(</span></span></span></span>_POST['user_email']);
}
if (isset($_POST['user_age'])) { // Corrected variable to user_age
<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mi>s</mi><mi>e</mi><msub><mi>r</mi><mi>a</mi></msub><mi>g</mi><mi>e</mi><mo>=</mo><mi>h</mi><mi>t</mi><mi>m</mi><mi>l</mi><mi>s</mi><mi>p</mi><mi>e</mi><mi>c</mi><mi>i</mi><mi>a</mi><mi>l</mi><mi>c</mi><mi>h</mi><mi>a</mi><mi>r</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">user_age = htmlspecialchars(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">u</span><span class="mord mathnormal">se</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span class="vlist-s"></span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mord mathnormal">e</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">h</span><span class="mord mathnormal">t</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">s</span><span class="mord mathnormal">p</span><span class="mord mathnormal">ec</span><span class="mord mathnormal">ia</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">c</span><span class="mord mathnormal">ha</span><span class="mord mathnormal">rs</span><span class="mopen">(</span></span></span></span>_POST['user_age']);
}
if (isset($_POST['user_feedback'])) {
<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mi>s</mi><mi>e</mi><msub><mi>r</mi><mi>f</mi></msub><mi>e</mi><mi>e</mi><mi>d</mi><mi>b</mi><mi>a</mi><mi>c</mi><mi>k</mi><mo>=</mo><mi>h</mi><mi>t</mi><mi>m</mi><mi>l</mi><mi>s</mi><mi>p</mi><mi>e</mi><mi>c</mi><mi>i</mi><mi>a</mi><mi>l</mi><mi>c</mi><mi>h</mi><mi>a</mi><mi>r</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">user_feedback = htmlspecialchars(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9805em;vertical-align:-0.2861em;"></span><span class="mord mathnormal">u</span><span class="mord mathnormal">se</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3361em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span></span></span></span><span class="vlist-s"></span></span><span class="vlist-r"><span class="vlist" style="height:0.2861em;"><span></span></span></span></span></span></span><span class="mord mathnormal">ee</span><span class="mord mathnormal">d</span><span class="mord mathnormal">ba</span><span class="mord mathnormal">c</span><span class="mord mathnormal" style="margin-right:0.03148em;">k</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">h</span><span class="mord mathnormal">t</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">s</span><span class="mord mathnormal">p</span><span class="mord mathnormal">ec</span><span class="mord mathnormal">ia</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">c</span><span class="mord mathnormal">ha</span><span class="mord mathnormal">rs</span><span class="mopen">(</span></span></span></span>_POST['user_feedback']);
}
if (isset($_POST['user_gender'])) {
<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mi>s</mi><mi>e</mi><msub><mi>r</mi><mi>g</mi></msub><mi>e</mi><mi>n</mi><mi>d</mi><mi>e</mi><mi>r</mi><mo>=</mo><mi>h</mi><mi>t</mi><mi>m</mi><mi>l</mi><mi>s</mi><mi>p</mi><mi>e</mi><mi>c</mi><mi>i</mi><mi>a</mi><mi>l</mi><mi>c</mi><mi>h</mi><mi>a</mi><mi>r</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">user_gender = htmlspecialchars(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9805em;vertical-align:-0.2861em;"></span><span class="mord mathnormal">u</span><span class="mord mathnormal">se</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span></span></span></span><span class="vlist-s"></span></span><span class="vlist-r"><span class="vlist" style="height:0.2861em;"><span></span></span></span></span></span></span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">h</span><span class="mord mathnormal">t</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">s</span><span class="mord mathnormal">p</span><span class="mord mathnormal">ec</span><span class="mord mathnormal">ia</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">c</span><span class="mord mathnormal">ha</span><span class="mord mathnormal">rs</span><span class="mopen">(</span></span></span></span>_POST['user_gender']);
}
}
// Display the submitted details
echo "<h2>Details Submitted:</h2>";
echo "Full Name: " . $fullname . "<br>";
echo "Email: " . $user_email . "<br>";
echo "Age: " . $user_age . "<br>";
echo "Feedback: " . $user_feedback . "<br>";
echo "Gender: " . $user_gender;
?> `
**Output:
**In this example:
- **HTML Form: Collects Full Name, Email, Feedback, and Gender using the POST method.
- **Form Submission: Data is sent back to the same page when the user submits the form.
- **PHP Processing: PHP retrieves data from the form using $_POST after submission.
- **Sanitization: htmlspecialchars() ensures the data is safe and prevents XSS attacks.
- **Displaying Data: PHP displays the submitted information back to the user.
**Conclusion
PHP form handling is an essential skill for web developers. By using PHP, you can capture and process user input securely and efficiently. Key steps in form handling include creating the form, collecting data, validating and sanitizing it, and optionally saving it to a database.