**Computer Science 15-110, Spring 2010
Recitation for Week #4**

**Return and Review Quiz2**-
**Review Hw3** **CA-Directed Lab****Student-Directed (Collaborative) Lab**

**Return and Review Quiz2**CA's will return and briefly review highlights of quiz2. Students needing deeper review of the material should set up a separate meeting with their CA or instructor.

**Review Hw3**CA's will briefly review highlights of hw3. Students needing deeper review of the material should set up a separate meeting with their CA or instructor.

**CA-Directed Lab****isPrime and nthPrime**

Under CA direction, write isPrime and nthPrime from scratch. Compare your solutions to the isPrime and nthPrime solutions in the class notes. Why does isPrime use a for loop whereas nthPrime uses a while loop?

**Nested Loops and Nested Loops with Graphics**

Review the course notes on Nested Loops and Nested Loops with Graphics. Be sure to understand how nested loops work!

**Student-Directed (Collaborative) Lab****Methods in the Class Notes**Be sure you can write all these methods (taken from the class notes) from a blank compiler without referring to the class notes!

**More Practice****Print the Digits of an Integer**Write a void method that takes an int n, and prints the digits of n from right-to-left, one per line. So, for the number 832, you would print 2, then 3, then 8. You may only use / and % for arithmetic (in particular, you may not construct powers of 10 in any way -- the clearest and most efficient solution does not require that).

**The sum of the digits of an integer**Write a method that takes a possibly-negative int and returns the (always-positive) sum of its digits.

**Letter Counter**Write a method that takes a String and a char, and returns a count of the number of times the given char occurs in the String. This method should be case-sensitive, so "Go Steelers" would contain the letter 's' only once.

**Case-insensitive Letter Counter**Repeat the previous problem, but this time make your test case-insensitive, so "Go Steelers" would contain the letter 's' twice.

**Even More Practice**Time permitting, CA's will offer even more problems for students to work on (say, using nested loops to create interesting 2d graphical patterns, though this is not a requirement).

**carpe diem -
carpe diem - carpe diem - carpe diem
- carpe diem - carpe diem -
carpe diem - carpe diem - carpe
diem**