What is difference between $_GET and $_POST?

Question

Sanjeeb Lenka · Answer

PHP provides two special functions called $_GET & $_POST this functions are used to get the values which are passed from a user-filled form like user registration or login form etc. $_GET is less secure and effective than $_ POST $_GET has few limitations like it can send about 100 words of data at a time whereas $_POST does not have such kind of limitations we can send any amount of data using this variable. $_POST is more secure than $_GET in the means of that whenever we send data from one web page to another using $_GET variable we can see the values in address bar on the contrary $_POST does not allow any thing to be displayed in address bar of the browser. Above mentioned difference is visible but subtle difference between these two is that $_GET method is idempotent that means according to HTTP specifications GET request is done when the request would not be changed on the other hand POST requests are not idempotent it should be used when there would have any possibility for changes. One GET request is for one URL and since GET method does not change browsers cached the response pages. On the other hand responses for POST method are not stored on the browser's cache memory. POST requests are ideal for queries whose response pages could change like placing an order updating database etc. Whereas GET requests are ideal for those queries whose responses could not change over a period of time. Let's check the difference with the help of examples: Example for $_GET: phpGet.html DOCTYPE html PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN http://www.w3.org/TR/html4/loose.dtd > html > head > meta http-equiv = Content-Type content = text/html; charset=ISO-8859-1 > title > Insert title here title > head > body > div align = center class = post dir = ltr id = post style = background-color:gray style = border:medium > form name = post method = post action = phpPost.php > font color = white > Enter your name: font > input type = text name = name > br /> font color = white > Enter Your age: font > input type = text name = age > br /> input type = submit value = submit > input > form > div > body > html > phpGet.php $name = $_GET [ 'name' ]; $age = $_GET [ 'age' ]; echo Howdy $name your age is: $age  ; ?> Output: Howdy sdfsdf your age is: 13 and the browser's address bar will be displayed as follows: http://localhost/php/phpGet.php?name=sdfsdf&age=13 On the other hand if you send these data using $_POST method process and output will be: There will be one small change in the html file that would be method=post as follows: phpPost.html DOCTYPE html PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN http://www.w3.org/TR/html4/loose.dtd > html > head > meta http-equiv = Content-Type content = text/html; charset=ISO-8859-1 > title > Insert title here title > head > body > div align = center class = get dir = ltr id = get style = background-color:gray style = border:medium > form name = get method = POST action = phpGet.php > font color = white > Enter your name: font > input type = text name = name > br /> font color = white > Enter Your age: font > input type = text name = age > br /> input type = submit value = submit > input > form > div > body > html > phpPost.php $name = $_POST [ 'name' ]; $age = $_POST [ 'age' ]; echo Howdy $name your age is: $age  ; ?> Output: Output will be same as before but the difference between these two will be reflected in the browser's address bar: Howdy DSFSD your age is: 42 Address bar will look as below: http://localhost/php/phpGet.php