| 1 | | == Conditionals |
| 2 | | Programs need to be able to react differently to varying data. Conditional statements let us do this. For example, a robot must be able to monitor its sensors to prevent collisions. Consider (and try running) the following program: |
| 3 | | * Create a new folder and new file; cut and paste this program into it and save it as !ConditionalExample.java |
| 4 | | {{{ |
| 5 | | public class ConditionalExample { |
| 6 | | public static void main(String args[]) { |
| 7 | | int rangeInInches; |
| 8 | | |
| 9 | | rangeInInches = 10; |
| 10 | | |
| 11 | | if (rangeInInches < 20) { |
| 12 | | System.out.println("stop motors so we don't crash!"); |
| 13 | | } else { |
| 14 | | System.out.println("full speed ahead!"); |
| 15 | | } |
| 16 | | } |
| 17 | | } |
| 18 | | }}} |
| 19 | | * Save the program as !ConditionalExample.java (notice how the name of the file must match the name of the class) |
| 20 | | * Run the program using the debugger with a breakpoint set on the first executable line (rangeInInches=10); step through the program using the stepover tool and observe the flow of the program. |
| 21 | | * What happens if you change the values stored in the variable rangeInInches to 25? |
| 22 | | |
