Assertions

Last modified Monday, 12-Feb-2024 15:28:56 UTC.

Assertions are used to sanity check programs
- Check that code is doing sane things
- Same idea as always using a default case in switch
- Not for user level errors
Assertions syntax
- assert <boolean condition> : <error value>
- When running the program, enable assertions with the -ea flag, e.g.,
```
java -ea ADodgyProgram 
```
  In IntelliJ ...
  - Choose Run -> Edit Configurations
  - Select the run configuration of interest.
  - Click on Modify options link and choose Add VM options.
  - Add -ea to the VM options box.
- If the <boolean condition> of an assertion is false then an error is thrown, and by default the program halts with an error message containing the <error value>
Example: Assert.java

Exercises