Java自定义一个ArrayList类

1.自定义一个MyArrays类：

public class MyArrayList {
    private int[] element;
    private int size;//有效个数

    public MyArrayList(){
        this.element = new int[10];
        size = 0;
    }
    private void grow(){//扩容
        element = Arrays.copyOf(element,element.length+(element.length>>1));
    }
	private void shorten(){
		element=Arrays.copyOf(element,element.length-1)
	}
    private void esureCapacity(){//检查行为
        if(size == element.length){
            grow();
        }
    }
    public void addTail(int value){//尾部添加
        //是否需要扩容
        esureCapacity();
        element[size] = value;
        size++;
    }
	public void addHead(int value){
		ensureCapacity();
		for(int i=0;i<=element.length;i++){
		element[i+1]=element[i];
		}
		element[0]=value;
	}
	public void deleteValue(int value){
		for(int i=0;ifromIndex;i--){
			for(int j=i;i