{"id":1891,"date":"2014-12-08T14:47:08","date_gmt":"2014-12-08T12:47:08","guid":{"rendered":"http:\/\/www.webcodegeeks.com\/?p=1891"},"modified":"2018-06-20T15:16:31","modified_gmt":"2018-06-20T12:16:31","slug":"php-form-validation-example","status":"publish","type":"post","link":"https:\/\/www.webcodegeeks.com\/php\/php-form-validation-example\/","title":{"rendered":"PHP Form Validation Example"},"content":{"rendered":"

EDITORIAL NOTE<\/strong>: In this post, we feature a comprehensive PHP Form Validation Example.<\/p>\n

Data is an integral part of an application. There is a golden rule for developers.<\/p>\n

Never trust your user’s information.<\/p><\/blockquote>\n

So, we need to always filter and validate the user entered before storing it in application’s database. In this article, we will learn how to perform basic validation of form in php.<\/p>\n

We will create a simple registration form which will contain various\u00a0inputs like textbox, checkbox, radio buttons and a submit button. After submitting the form, we will validate the fields with php and show error messages if there are some errors.<\/p>\n

[ulp id=’8njY7i2QRy6sg8pg’]<\/p>\n

Contact Form<\/h1>\n
\"The<\/a>
The Registration Form<\/figcaption><\/figure>\n

Text Fields<\/h1>\n

The name and email are the text input<\/code> elements of the form and can be coded like this :<\/p>\n

\r\n\r\n<input class="input" type="text" name="name" value="">\r\n\r\n<input class="input" type="text" name="email" value="">\r\n\r\n<\/pre>\n
The basic text input is created using the\u00a0input<\/code> tag by setting the type<\/code> to\u00a0text<\/code>. The initial contents of the\u00a0input<\/code> can be specified using the\u00a0value<\/code> attribute. If you do not include this attribute, or if you specify an empty value<\/code>, there will be no contents by default. The text input\u00a0is a single line input accepting any normal text characters, but not linebreaks. If the contents are too large to fit, the\u00a0input will scroll, usually without a visible scrollbar.<\/p>\n
Radio Buttons<\/h1>\n
\r\n\r\n<input type="radio" name="technologies" value="PHP"> PHP\r\n\r\n<input type="radio" name="technologies" value="HTML"> HTML\r\n\r\n<input type="radio" name="technologies" value="PYTHON"> Python\r\n\r\n<\/pre>\n
A radio button is created using the input<\/code>\u00a0element, by setting the type<\/code>\u00a0attribute to radio<\/code>. Radio buttons are put into groups by giving them the same\u00a0name<\/code>\u00a0attribute, and you can have multiple radio groups in a form<\/code>. To pre-select a radio input, set the checked<\/code>\u00a0attribute on the desired input (this is another attribute that does not need a value). You should never attempt to pre-select more than one radio input in a group.<\/p>\n
Textarea<\/h1>\n
\r\n\r\n<textarea name="message" val=""><\/textarea>\r\n\r\n<\/pre>\n
A textarea<\/code> is a larger version of a text<\/code> input<\/code> that can contain multiple lines of text, including linebreaks. Most browsers will display a scrollbar if the contents are too large for the textarea<\/code>.<\/p>\n
Textareas are created using the textarea<\/code> tag. This requires a closing tag, and has no value<\/code> attribute. Instead, the default value is written in between the opening and closing tags. It requires that you provide the rows<\/code> and cols<\/code> attributes, which give a suggestion for an initial size (based on the number of characters that should be displayed vertically and horizontally). This is a little unusual, since it forces you to specify display related information in the HTML, but you can always override them using the height<\/code> and width<\/code> styles in CSS.<\/p>\n
File Input<\/h1>\n
\r\n\r\n<input class="input" type="file" name="resume">\r\n\r\n<\/pre>\n
This allows the user to choose a file that will be uploaded to the server. There are obvious security issues here, so in order to prevent pages uploading files without permission, browsers will not allow HTML or script to set the initial value of the input.<\/p>\n
When you make a POST<\/code> request, you have to encode the data that forms the body of the request in some way.<\/p>\n
HTML form<\/code> provide three methods of encoding.<\/p>\n