myArr.java

import java.lang.reflect.Array;

public class myArr<E> {

    //inner class that lets you zip a list into pairs
    public class Pair<F, S> {
        private F first;
        private S second;

        public Pair(F first, S second){
            this.first = first;
            this.second = second;
        }

        public F getF(){
            return this.first;
        }

        public S getS(){
            return this.second;
        }

        public String toString(){
            String out = "";
            out += "(" + this.getF() + ", " + this.getS() + ")";
            return out;
        }
    }

    public myArr(){}

    //returns element at given index
    public E get(E[] data, int index){
        return data[index];
    }

    //removes from array at index
    @SuppressWarnings("unchecked")
    public E[] take(E[] data, int index){
        E[] newData = (E[])new Object[data.length - 1];
        //might need a check for if index is greater than data.length
        for(int i=0; i<index; i++){
            newData[i] = data[i];
        }
        for(int i=index; i<data.length-1; i++){
            newData[i] = data[i+1];
        }
        return newData;
    }

    //inserts element at given index in array
    @SuppressWarnings("unchecked")
    public E[] insert(E[] data, int index, E item){
        //check if index in range
        E[] newData = (E[])new Object[data.length+1];
        for(int i = 0; i < index; i++){
            newData[i] = data[i];
        }
        newData[index] = item;
        for(int i = index + 1; i < newData.length; i++){
            newData[i] = data[i-1];
        }
        return newData;
    }

    //zips up two lists by creating pairs
    // be sure to check that they're the same length!
    @SuppressWarnings({"unchecked", "rawtypes"})
    public Pair<E, E>[] zip(E[] first, E[] second){
        Pair<E, E>[] zipped = new Pair[first.length];
        for(int i = 0; i < first.length; i++){
            zipped[i] = new Pair(first[i], second[i]);
        }
        return zipped;

    }

    public String toString(E[] data){
        String out = "";
        out += "[";
        for(int i = 0; i < data.length - 1; i++){
            out += data[i].toString() + ", ";
        }
        out += data[data.length-1].toString() + "]";
        return out;
    }

    @SuppressWarnings({"unchecked", "rawtypes"})
    public static void main(String[] args){
        myArr a = new myArr();

        Object[] A = new Integer[] {1, 2, 3, 4, 5};
        Object[] B = new Integer[] {1, 4, 9, 16, 25};


        System.out.println("A: " + a.toString(A));
        System.out.println("B: " + a.toString(B));


        System.out.println("Item at 2nd index of B: " + a.get(B, 2));
        System.out.println("Item at 2nd index of A: " + a.get(A, 2));
        System.out.println("Zipped lists: ");
        System.out.println(a.toString(a.zip(A, B)));

        System.out.println("Removing item at 3rd index of B and A: ");
        A = a.take(A, 3);
        B = a.take(B, 3);
        System.out.println("B: " + a.toString(B));
        System.out.println("A: " + a.toString(A));

        System.out.println("Inserting items at end of A and B: ");
        A = a.insert(A, A.length, 6);
        B = a.insert(B, B.length, 36);
        System.out.println("B: " + a.toString(B));
        System.out.println("A: " + a.toString(A));

        System.out.println("Zipping again: ");
        System.out.println(a.toString(a.zip(A, B)));

        System.out.println("\n-----------------------\n");

        System.out.println("With strings: ");
        Object[] C = new String[] {"Apple", "Broccoli", "Potato"};
        Object[] D = new String[] {"Fruit", "Vegetable", "Root"};
        System.out.println("C: " + a.toString(C));
        System.out.println("D: " + a.toString(D));
        System.out.println("Removing item at 1st index of C and D: ");
        C = a.take(C, 1);
        D = a.take(D, 1);
        System.out.println("C: " + a.toString(C));
        System.out.println("D: " + a.toString(D));
        System.out.println("Inserting item at 1st index of C and D: ");
        C = a.insert(C, 1, "Hummus");
        D = a.insert(D, 1, "Dip");
        System.out.println("C: " + a.toString(C));
        System.out.println("D: " + a.toString(D));
        System.out.println("Zipped lists: ");
        System.out.println(a.toString(a.zip(C, D)));




    }

}