Sams Teach Yourself PHP in 24 Hours, Third Edition

Q&A

Q1:	Must a control structure’s test expression result in a Boolean value?
A1:	Ultimately, yes. However, in the context of a test expression, zero, an undefined variable, or an empty string is converted to false for the purposes of the test. All other values evaluate to true.
Q2:	Must I always surround a code block in a control statement with brackets?
A2:	If the code you want executed as part of a control structure consists of only a single line, you can omit the brackets. The code examples in this book retain brackets to promote readability. Retaining the brackets for single-line control statements can also help guard against bugs as new lines are added to the block over time.
Q3:	Does this hour cover every kind of loop there is?