Adding an Array of Values to an already existing Array

Question

I'm trying to add an Array with values to an already existing Array which already has one value. My approach, was to create a new Array with the length of the already existing one + the length of the values i want to add. Then i would just loop through the whole Array and add the values to the index of the new Array. My Approach looks like this:

public void addValues(int[] values) {
        int[] array = new int[data.length + values.length];
            for(int i = 0; i < array.length; i++) {
            array[i] = values;
        }
        data = array;
}

Where as "data" is the already existing Array My appraoch fails because of multiple things,

I can't convert "array[i] = values"
I don't have the values of "old" Array

I can't think of a Solution

If you can declare array of length to data.length + values.length while print array you get error Index out of bound because array.length > values.length — Faheem azaz Bhanej
– Faheem azaz Bhanej, Commented Oct 31, 2021 at 9:02

Thomas Kläger · Accepted Answer · 2021-10-31 11:46:40Z

1

You are on the right track: you need to allocate a new array that can hold all data. But after that you need to copy the existing data into the new array followed by the values :

private int[] data; // assuming this exists somewhere

public void addValues(int[] values) {
    int[] array = new int[data.length + values.length];
    for (int i = 0; i < data.length; i++) {
        array[i] = data[i];
    }
    for (int i = 0; i < values.length; i++) {
        array[data.length + i] = values[i];
    }
    data = array;
}

Actually you can even use some methods to reduce the code size:

public void addValues(int[] values) {
    int[] array = new int[data.length + values.length];
    System.arraycopy(data, 0, array, 0, data.length);
    System.arraycopy(values, 0, array, data.length, values.length);
    data = array;
}

answered Oct 31, 2021 at 11:46

Thomas Kläger

21.9k3 gold badges30 silver badges40 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Adding an Array of Values to an already existing Array

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related