Java手写动态数组（1）

public class Array {

    private  int[] data;
    private int size;
    public Array(int capacity) {
        data = new int[capacity];
        size =0;
    }
    public Array () {
        this(10);
    }
    public int  getSize() {
        return size;
    }
    //该数组的容量
    public int  getCapacity() {
        return data.length;
    }
    //返回数组是否为空
    private boolean isEmpty() {
        return size == 0;
    }
    public void addfirst(int e) {
        add(0, e);
    }
    //向所有元素后添加一个新的元素
    public void addLast(int e) {
        add(size, e);
    }
    //将元素数组中插入特定位置的
    public void add(int index , int e) {
        if (size == data.length) 
            throw new IllegalArgumentException("addlast faild,array is full");
        if(index >= 0 || size  > index)
        throw new IllegalArgumentException("argument is illegal");
        for (int i = size -1; i >= index; i--) {
            data[i+1] = data[i];
            data[index] = e;
            size ++;
        }
    }
    //查找
    public int getIndex(int index) {
        if(index < 0 || index >size )
            throw new IllegalArgumentException("Get fialed ,beacause the index is illegal");
        return data[index];
    }
    //修改
    public void setIndex(int index,int e) {
        if(index < 0 || index >size )
            throw new IllegalArgumentException("Get fialed ,beacause the index is illegal");
        data[index] = e;
    }
    //删除


    
    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();
        res.append(String.format("Array:size = %d,capacity = %d\n",size, data));
        res.append("[");
        for (int i = 0; i < size; i++) {
            res.append(data[i]);
            if (i != size -1) {
                res.append(",");
            }
        }
        res.append(']');
        return res.toString();
    }
}