| 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? | 
| A3: | No. In Hour 7, you'll encounter the foreach statement, which enables you to loop through every element in an array. |