Quick introduction to PHP (2)_PHP tutorial

Form processing

PHP provides users with many convenient and easy-to-use powerful functions. In terms of form processing, PHP can automatically assign the data sent by the client form to the corresponding variables, thus greatly simplifying the entire form processing process.

For example, the user creates the following form:

< INPUT TYPE=TEXT NAME=“name” VALUE=“PETER” >

When using PHP for the above When the code is processed, PHP automatically creates a variable named $name and assigns the variable value "PETER" to the variable.

Users can directly perform various operations on variables created by PHP, such as displaying variable values:

echo "Hi $name!";

or verifying variable values :

if ($name == “PETER”) { echo “Please check out your email.”; }

Next, let’s take a look at how to create and process an email using PHP Basic form. In the example, we will ask the form filler to answer a few short questions, including entering the form filler's name, email address, completing a questionnaire, etc.

Here, we divide the page we want to design into two functional modules: form display and form processing. In this way, users do not have to design two different pages, but only need to display or process the corresponding functional modules through logical control in the same PHP page. A. Form display

We implement the form display through the first functional module. The specific code is:


function display_form()

{

global $PHP_SELF;

? >


< FORM TARGET="< ?php echo $PHP_SELF; ? >"METHOD=GET >

Name: < INPUT TYPE=TEXT NAME= "name" >< BR >

Favorite Fruit: < INPUT TYPE=RADIO NAME=“fruit” VALUE=“apple” >Apple

< INPUT TYPE=RADIO NAME=“fruit” VALUE=“orange” >Orange

< INPUT TYPE=RADIO NAME=“fruit” VALUE=“banana” >Banana

Favorite Times to Eat Fruit:

< INPUT TYPE=CHECKBOX NAME=“times[]” VALUE=“m” >Morning

< INPUT TYPE=CHECKBOX NAME=“times[]” VALUE=“n ” >Noon

< INPUT TYPE=CHECKBOX NAME=“times[]” VALUE=“d” >Dinner

< INPUT TYPE=CHECKBOX NAME=“times[]” VALUE=“l” >Latenight

< INPUT TYPE=HIDDEN NAME=“stage” VALUE= “results” >

< INPUT TYPE=SUBMIT VALUE= “Thanks!” >

< /FORM >


< ?php

}

? >

Above The vast majority of the code is the HTML code necessary to create the form. Here, we only give a brief introduction to the PHP knowledge involved.

First, let’s take a look at the variable $PHP_SELF at the beginning of the code. The variable $PHP_SELF is a very convenient pointer in PHP, and its variable value is the URL address of the current page. In this way, we can achieve the purpose of processing the form by the form page by setting the value of TARGET to $PHP_SELF in the subsequent form tag. Here, we use the $PHP_SELF variable instead of the actual address of the page, because by using the $PHP_SELF variable, we can easily modify and move the page code we write without having to worry about re-entering the new page address after each change. .

In addition, when using the $PHP_SELF variable, we adopt the following method:

global $PHP_SELF;

This indicates that the $PHP_SELF variable in the code is a global variable. When using PHP, users must note that any function variables in PHP are local variables. This means that the scope of any function variable is limited to the function itself that contains the variable. Even if a variable with the same name exists outside the function, the value of the variable is different. Therefore, if we do not explicitly declare the function variable $PHP_SELF as a global variable with a globally unique value in the code, the user will find that the value of the variable $PHP_SELF in the function will be empty, not what we expected in advance. The URL address of the current page.

Users may have noticed that we set the name of the form check option to a times[] array, and set the name of the radio option to a fruit regular variable. This is because the radio option only allows the user to select one correct option, so the value of the fruit variable can only be a string; on the contrary, the check option allows the user to make multiple choices. If the user wants PHP to save all the choices the user may make, he or she needs to use an array to save all possible values. According to PHP's syntax rules, we add square brackets after the variable name times to let PHP know that the variable is an array variable rather than an ordinary regular variable.

Finally, we set an implicit variable called stage. By using this variable, we can control whether to display the form or process the form results. ​

http://www.bkjia.com/PHPjc/314006.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/314006.htmlTechArticleForm processing PHP provides users with many convenient and easy-to-use powerful functions. In terms of form processing, PHP can automatically assign the data sent by the client form to the corresponding variables, thus...