$ Url = "show. php? Catid = ". ($ row ['catid']); instructions-php Tutorial

$ Urlshow. php? Catcatid]); $ url = "show. php? Catid = ". ($ row ['catid']);

Will the content in show. php be automatically called During code execution ??? In the middle? Can catid = be written as needed, for example, $ url = "show. php? Topic = ". ($ row ['catid']);

Reply to discussion (solution)

This is just to generate a string for the link. you can click it to run shop. php... the catid can be changed at will, but the variable names in the shop. php file must be consistent.

? Id = ". row ['catid']";

IDs can be defined at will, but row ['catid'] should be unique
When the value is passed, it depends on the parameter.

$ Url = "show. php? Catid = ". ($ row ['catid']);
This code assigns a value to $ url. The value is a string and the content is show. php? Catid = $ row ['catid'] content

There is no content that calls show. php.
The catid is a parameter name that can be written at will, but the page for obtaining parameters must be modified accordingly.
For example, show. php? Catid = 1 so you need to GET $ _ GET ['catid'] in show. php.
If show. php? Id = 1. you need to obtain $ _ GET ['id'] in show. php.