在Java中递归查找数组的长度

Question

I'm trying to make a method that returns the length of an array recursively (as a learning exercise). I tried passing in an array of length 4, but the method just returns 1. I also tried calling the recursive method outside of the if statement and that just gives a StackOverflowError. Why is this method returning one and how can I get it to return the correct length?

public static int findArrayLength(int i, int length, int[] array) {
        
        if(i < array.length) {
            length += 1;
            i++;
            findArrayLength(i, length, array);
        }
        return length;
    }

Answer 1

You're not using the result of the recursive call, also you can replace the increment, to a +1 inside the recursive call, and i and length are doing same, keep one only

public static int findArrayLength(int i, int[] array) {
    if (i < array.length) {
        return findArrayLength(i + 1, array);
    }
    return i;
}

System.out.println(findArrayLength(0, new int[]{1, 1, 1})); // 3
System.out.println(findArrayLength(0, new int[]{1, 1, 1, 1})); // 4
System.out.println(findArrayLength(0, new int[]{1, 1, 1, 1, 1})); // 5