What is the difference between the get and post methods? Passing Variables in PHP
You may have noticed that on most sites you can see the following addresses:
Http://site/index.php?blog=2
Here, even without knowing php, you can guess that we are accessing a file index.php But few people know what comes after the question mark. It's quite simple: ?blog=2 This is a declaration of the global variable "$_GET["blog"]" with the value "2". Thus, I pass a variable into the script that is responsible for displaying information from the database. Let's write a small script in which you can clearly see everything:
if(isset($_GET["blog"])) (
echo $_GET["blog"];
}
?>
We use the if() condition operator and the following line is used as a condition:
Isset($_GET["blog"])
isset() allows you to find out whether the variable specified in brackets exists, that is, the condition that I described in the code sounds like this: If the variable $_GET["blog"] exists, then display the contents of this variable on the screen. Here's what happened:
I think it’s clear A global variable is created $_GET with the identifier that we declared in the address bar ( in this case with the identifier “blog”)
Now I want to clarify one point. Suppose we need to declare two variables, how to do this? The first variable is declared after the question mark "?" The second variable is declared after the “&” sign ( To be honest, I don’t know what this sign is), here is an example declaration of three variables:
Http://site/index.php?a=1&b=2&c=3
Here is the output code:
if(isset($_GET["a"]) AND isset($_GET["b"]) AND isset($_GET["c"])) (
echo $_GET["a"]."
";
echo $_GET["b"]."
";
echo $_GET["c"]."
";
}
?>
The condition sounds like this:
If there is a global variable $_GET["a"] and a global variable $_GET["b"] and a global variable $_GET["c"] then display them on the screen, here is the result:
Forms
Before we get to post requests, you need to understand what forms are? Why is it necessary? Because the global variable $_POST[""] is created through forms. What is form? These are fields for the user to enter some information. There are one-line fields, large fields, and also radio buttons and check boxes. Let's take everything in order...
The form is a tag:
The form has attributes, I will list the most common ones:
Let's create a form:
I set the file as a handler file test.php since it is in it that I write examples for you. I set the sending method to post because these are the methods used in 99.9% of cases. I also gave our form a name - form
Now let's plunge into the world of form elements. The first thing you need to understand is that almost all elements are a tag the only difference is in the attribute type at these tags. Let me list the form elements used:
I’m sure you’ve seen such fields more than once, so here’s what they say: “no comments”
Now let's create a small training questionnaire, which we will work with further. Our task is to create a small questionnaire that will tell us the name of the person filling it out, gender, what country they are from, favorite color and a text field where the user can add something about themselves. Here's what I got:
If the user enters some text into the text field and clicks on the “Submit” button, the text variable will be sent to the server with the value of the content that the user entered.
POST and GET requests in simple words
This variable will be sent using the POST method.
If you write this in the form: