Menggunakan klausa If dalam PHP Use if clause in PHP Programming

Ok man now. we will study how to implement if clause in PHP programming.
If used at conditional programming.  There are two choices, or there are two states.
I mean, in our live we always face two state, true or false. true is the state according that we want, and false is the state inaccording that we want.

Example:
If you want to display a costumer list in a system that you have. Your system can't find the list. It is a false.  but if list displayed on your computer, it is true.
Do you understand now.