Thread: Help with Class Methods(Probably simple)

Jake here, im new to this forum, im also new to java and recently got a bit stuck in a programming exercise for my module. I know it'll probably be really easy to some people but i thought id share it because im still only learning.The question is as follows:

Write a class method which calculates the power of one number raised to another. The method would be used as follows:

	int x = getPower(2, 5); // 2 to the power of 5 = 32
	int x = getPower(3, 4); // 3 to the power of 4 = 81

Use this method to print the first 20 powers of 2.

The class method i will use will be something like this:

static int getPower(int num, int power){
 
}

Im basically just confused about how i would go about doing this and whether or not i need to use a for loop. Any help would be greatly appreciated.
Thanks and il look forward to talking with you all throughout the forum

First suggestion, use a new variable to hold the results, don't reuse num.
You need a loop where you multiply the result by num while using the value of power to control the number of times thru the loop.

Look at this:
power=2 result= num*num
power=3 result=num*num*num
power=4 result=num*num*num*num
See how for each higher value of power you multiply the result by num one more time.

Alternatively, you can do something like this:

a^b = c
b * ln(a) = ln(c)

where ln is the natural logarithm.

Now all you have to do is use a logarithm table and extrapolate to an answer, or use the "nearest neighbor" method with a logarithm table (alternatively you can call the exp() method to do the first method for you).

Without using this, though, you would want to use a loop of some kind (either a while or a for loop), and iterate from 0 to the exponent number. Inside the loop you just need to multiply the result (originally 1) by the base.

Thanks alot i solved it just there with all of your help It was just a small question out of an exercise sheet that confused me and I hate moving on and leaving questions unsolved. Incase you were wondering this was my solution.

class Powers{		
	static int pow(int x, int y){
		int result = 1;
		for(int z = 0; z < y; z++){
			result = result * x;		
		}
		return result;
	}
 
	public static void main(String [] args){
		int num;
		for(int i = 1; i < 21; i++){
			num = pow(2, i);
			System.out.println("2 to the power of " + i + " = " + num);
		}
	} 
}

Feel free to suggest some tips for future coding as i am here to continue learning more Thanks again.