Previously, we created a form under an HTML page in the HTML form learning article.
This form is used by users to enter data
The specific code is as follows
<!DOCTYPE HTML><HTML><Head><MetaCharSet= "Utf-8"></Head><Body><H1>User Login</H1><formname= "Input"Action= "action.php"Method= "POST">Account Number:<inputtype= "text"name= "User"><BR><BR>Password:<inputtype= "Password"name= "pwd"><BR><BR>Gender:<inputtype= "Radio"name= "Sex"value= "Man">male<inputtype= "Radio"name= "Sex"value= "Woman">female<BR><BR>Hobbies:<inputtype= "checkbox"name= "hobby[]"value= "Basketball">Basketball<inputtype= "checkbox"name= "hobby[]"value= "Football">Football<inputtype= "checkbox"name= "hobby[]"value= "Badminton">Badminton<BR><BR> <inputtype= "Submit"value= "Submit"> </form></Body></HTML>
We see that there are two properties in the form label, one of which is action and the other is method
When we click the Submit button, the content is transferred to the PHP file specified by the action.
And in PHP there is a super global variable $_post
This super global variable, $_post, is used by PHP to receive the form data, but it does not implement the receive effect until you specify post in the form properties method.
Then we give the contents of the action.php file:
<?PHP$user=$_post[' User ']; $pwd=$_post[' pwd '];$sex=$_post[' Sex '];$hobby=isset($_post[' hobby '])?$_post[' Hobby ']: "";Echo"Your account number is:",$user, "<br>"; Echo"Your password is:",$pwd, "<br>"; Echo"Your sex is:",$sex, "<br>"; Echo"Your hobby is:";if(Is_array($hobby)){ foreach($hobby as $x){ Echo $x. " "; }}
?>
By clicking the Submit button, the data is then transferred to the action.php page, and our browser jumps to this page.
We can see that the variable that we use to receive the data is $_post, which puts the name value of the form element, which will be transferred to these variables of PHP.
It is worth noting that we are in the HTML page, the name of this check box is hobby[], because the check box to transfer multiple arrays, so its name should be an array of form.
Otherwise, only one value is passed to the variable, and we need a set of values for the check box.
Of course, although the check box in the HTML page name is hobby[]
But we are still $_post[' hobby ' when we receive it, and this stuff is actually an array.
This time we need to do a protective measure, in order to prevent sometimes our check box is nothing to choose the null value, rather than an array, this time we do a test
$hobby=isset($_post[' hobby '])? $_post [' Hobby ']: "";
The isset () function is used to detect if a variable is set and is not NULL.
If it is empty, then $hobby also give null value, if not empty, then $hobby this variable is the check box of the entire array of contents.
Then we use a foreach loop to output this array and show it.
if (is_array($hobby)) { foreach($hobbyas$x) { echo$x . " "; }}
The is_array () function is used to detect if a variable is an array, and if it is an array, it is displayed, if it is not an array, do not do any action.
Line breaks in PHP can be replaced with php_eol to improve code-level portability
Well, here we have the first HTML and PHP interactive case has been done.
This is also an interactive case of our first front end and back end.
HTML is the front-end, as the customer's browsing interface, PHP is executed on the server side of the program, is the backend, this through the case to deepen our understanding of the front-end and back-end, browser-side and server-side.
And then after this interaction, the next thing we do is the interaction between PHP and MySQL, that is, to save the PHP value to the server-side database based on this case.
You know, if we do not save, then each time we get the data will disappear, and only save it, the data will not disappear, and every time we open a page, we will show all of our previous content
OK, we'll start with the next essay on PHP and MySQL interaction.
PHP Full Stack development (vi): PHP interacts with HTML pages