CSIS 110 – Lecture 7
Quiz: Wednesday. Material in Chapters 1 and 2.
Read: Chapter 3, section 3.1 to 3.11.
Partner assignment sheets
Quiz Review – Go over review questions that I handed out last time.
Last Time
We looked at the NumberDisplay class:
- Abstraction and modularization
- boolean operations: &&, ||, and !
Review boolean operations. Give some example boolean expressions and ask students to
evaluate.
So, what would happen if we replaced the && operator with || in the setValue
method?
The accessor method getDisplayValue
This method also gets the value, but as a String instead of an int. What is it doing?
if ( value < 10 )
return “0” + value;
else
return “” + value;
What’s going on here?
- What does the expression “0” + value do?
- What does the expression “” + value do?
- Statements after return statement?
- What’s the purpose of this if statement?
Does this method work correctly in all cases? Does it make any assumptions? What if the
value of limit is 500?
The increment method
The increment method adds 1 to the value, but has to reset it to 0 if the limit is reached.
This method uses the modulo operator:
value = ( value + 1 ) % limit;
