newbie question - if statements without conditions

Hello,
trying to understand some code I've been using and I often come across if statements without actual conditions. for example:

Code:

---

if(bcs)
{
 statements
}

---

(bcs is an integer here)

why is there no condition statement? is there a default for if statements (enter the loop if bcs is defined?)?

thanks

bcs is false if it is zero. bcs is true if it is not zero.

thanks!