Monday, January 3, 2011

Program to Print the First 10 values 2 to the kth Power

Problem: Write a method raiseIntToPower that takes two integers, "n" and "k" and returns n to the kth power. Use your method to display a table of values 2 to the kth power for all values of k from 0 to 10. (Robers ch 5, problem 3).

What it looks like:

How long it took: 30 min or so

What made it difficult: There are two loops in this problem. One says "From i being 0 to 10, print 2 to the i." The second loop is inside the private method, and it says "From i = 0 to the specified kth power, multiply the base by itself." Both loops use the same variable "i," and I can see a program like this getting confusing. However, it's unavoidable that you'll use the same variable name within a program; that I assume is because methods are built to be re-usable, so you'll never know which program you'll plunk them into.

I felt pretty comfortable with this re-use of "i" because both the book and Mehran's lecture went through tracing a program similar to this throughout multiple method calls and parameter passes. Going through strack frames in excruciating detail like this made me really aware of the "life cycle" of a program. Definitely a good foundation when learning about using private methods.


* File:
* Name: Chu
* Section Leader: 
* Description: This program asks us to write a program that writes out 2 to the nth power for
* n = 1 to n = 10. We accomplish this using the private method 'raiseIntToPower', which can take in
* any base and any raised power.

package ch6_practice;
import acm.program.*;

public class RaisePowerWithMethod extends ConsoleProgram {
    public void run() {
        for(int i = 0; i < 10; i++) {
            println (raiseIntToPower(2, i));
    private int raiseIntToPower(int n, int k) {
     int result = 1;
     for (int i = 0; i < k; i++) {
      result *=n;      
     return result;

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