玩转数据结构02 数组

import java.util.Scanner;
import java.util.Random;

public class Main {
    public static void main(String[] args) {
        Random ra = new Random();

        System.out.println("ra is " + ra.nextInt(10));

        int[] arr = new int[3];
        for (int i = 0 ; i < arr.length; i ++)
        {
            arr[i] = i;
            System.out.println(arr[i]);
        }

        int[] srcores = new int[]{100, 88, 96};
        for(int i = 0; i < srcores.length; i ++)
        {
            System.out.println(srcores[i]);
        }

        System.out.println("醉里挑灯看剑");
        for(int score: srcores)
            System.out.println(score);

        System.out.println("醉里挑灯看剑");

        srcores[1] = 68;
        for(int i = 0; i < srcores.length; i ++)
        {
            System.out.println(srcores[i]);
        }
        
    }

}

public class Array {

    private int[] data;
    private int size;

    //有参构造函数
    public Array(int capacity)
    {
        data = new int[capacity];
        size = 0;
    }
    //无参构造函数
    public Array(){
        this(10);
    }

    public int getSize(){
        return size;
    }

    public int getCapacity(){
        return data.length;
    }

    public boolean isEmpty(){
        return size == 0;
    }

    public void addLast(int e){

        add(size, e);
    }

    public void addFirst(int e)
    {
        add(0, e);
    }

    public void add(int index, int e){
        if (size == data.length)
        {
            throw new IllegalArgumentException("addlast failed, array is full.");
        }

        if (index < 0 || index > size){
            throw new IllegalArgumentException("add failed,Require index < 0 || index > size.");
        }

        for (int i = size - 1; i >= index; i--){
            data[i + 1] = data [i];
        }
        data[index] = e;
        size ++;
    }

}