编译错误-有人可以纠正我吗？

Question

I just created a code which represents the sum of integer values from 1 to 10.

public class ArithmeticProgress {

    public static void main(String args[]) {
        int i = 10;
        int n;
        System.out.println(arithmeticprogress(n, i));
    }

    static int arithmeticprogress(int n, int i) {
        int result = n;
        for (n = 0; n < i; n++)
            result += result;
        return result;
    }
}

Unfortunately, it does not compile and therefore it only shows error. Can somebody tell me how to correct this code? Thank you!

Answer 1

You need to initialize n here.

int n=10; // initialize n to some value
System.out.println(arithmeticprogress(n, i)); //else you will get error here

Use IDE to coding. Then you will get

int n;
System.out.println(arithmeticprogress(n, i));//'n' might not be initialize

Or else you can use n as class level variable. Then it will set to it's default value.

Answer 2

As int n; declare in method main, it won't be initialized as it is a local variable and local variable are not initialized automatically. You need to initialize it explicitly before use. So changing it to int n=0; will work.

Answer 3

You are getting compilation error because in java local variables are stack variables and they must be initialized before they can be used. In your case variable n is used before it is initialized. Initialized it like this and it should work.

int n= 1; 

Answer 4

There are two problem in your code.
1. You must need to initialize local variable before to use it. You need to initialize n to 0 or any other value which is applicable for your logic.

2. If you want to get the sum of integer from 1 to 10 than your logic is incorrect that's why you got 1024 as a result ( If you initialize n=1 ). you are adding your current result to previous result which is incorrect. To simply add integer from 1 to 10 i think you didn't need variable n in you code.

For this your method should be as shown below :

static int arithmeticprogress(int i) {
    int result = 0;
    for (int n = 1; n <=i; n++)
        result = result + n;
    return result;
}  

It will gives you result as 55 which is summation of 1 to 10 integer number.

May this will help you.