排除数组的第一个和最后一个元素

Question

I am trying to display array elements where all elements undergo a change, but the first and last element should remain the same.

Currently I have no idea on how to leave the first and last element alone.

    public static void main(String[] args) {
        int num = 3;
        int [] array = {2, 3, 2, 5, 3, 1};

        int[] n = increaseValues(array, num);
        System.out.println(Arrays.toString(n));
    }//end of main
    
    public static int[] increaseValues (int array[], int num){
        int newArray[] = new int[array.length];
        for(int i = 0; i < array.length; i++){
            newArray[i] = array[i] * 3;
        }
        return newArray;
    }//end of method

The current output is: 6, 9, 6, 15, 9, 3

Output should be: 2, 9, 6, 15, 9, 1

How should would I implement this?

Answer 1

You can change the function as this,

public static int[] increaseValues (int array[], int num){
    for(int i = 1; i < array.length-1; i++){
        array[i]= array[i] * 3;
    }
    return array;
}

So what happens is you will take the array object then it will loop from 1st element to array.length-1 element and do the changes.

the output will look like this,

[2, 9, 6, 15, 9, 1]

Answer 2

public static int[] increaseValues(int array[], int num) {
    int newArray[] = new int[array.length];
    for (int i = 1; i < array.length - 1; i++) {
    if (i == 0 || i == array.length - 1) {
        newArray[i] = array[i];
    } else {
        newArray[i] = array[i] * 3;
    }
        array[i] = array[i] * 3;
    }
    return array;
}//end of method

output

[2, 9, 6, 15, 9, 1]