Question
Write a method called printPowersOfN that accepts a base and an exponent as arguments and prints each power of the base from base0 (1) up to that maximum power, inclusive. For example, consider the following calls:
printPowersOfN(4, 3);
printPowersOfN(5, 6);
printPowersOfN(–2, 8);
These calls should produce the following output:
1 4 16 64
1 5 25 125 625 3125 15625
1 –2 4 –8 16 32 64 –128 256
You may assume that the exponent passed to printPowersOfN has a value of 0 or greater. (The Math class may help you with this problem. If you use it, you may need to cast its results from double to int so that you don’t see a .0 after each number in your output. Also try to write this program without using the Math class.)
Answer
Program using Math class:
public class Ch03Ex03
{
public static void main(String[] args)
{
printPowersOfN(4, 3);
printPowersOfN(5, 6);
printPowersOfN(-2, 8);
}
public static void printPowersOfN(int base, int maximum)
{
for (int i = 0; i <= maximum; i++)
{
System.out.print((int) Math.pow(base, i) + " ");
}
System.out.println();
}
}
Program without using Math class:
public class Ch03Ex03
{
public static void main(String[] args)
{
printPowersOfN(4, 3);
printPowersOfN(5, 6);
printPowersOfN(-2, 8);
}
public static void printPowersOfN(int base, int maximum)
{
int result = 1;
System.out.print(result + " ");
for (int i = 1; i <= maximum; i++)
{
result *= base;
System.out.print(result + " ");
}
System.out.println();
}
}
Output:
1 4 16 64
1 5 25 125 625 3125 15625
1 -2 4 -8 16 -32 64 -128 256