数据结构之动态数组--接上篇

//重置数组大小长度
    private void resize(int newCapacity){
        E[] newData = (E[]) new Object[newCapacity];
        for(int i = 0 ; i < size ; i ++)
            newData[i] = data[i];
        data = newData;
    }

main方法

package com.practice;

import com.practice.Array.Array;

public class Main {

    public static void main(String[] args) {
    // write your code here
        Array<Integer> arr = new Array<Integer>();
        for(int i = 0 ; i < 10 ; i ++)
            arr.addLast(i);
        System.out.println(arr);

        arr.add(1,100);
        System.out.println(arr);

        arr.addFirst(-1);
        System.out.println(arr);



        /*arr.remove(2);
        System.out.println(arr);

        arr.removeElement(4);
        System.out.println(arr);

        arr.removeFirst();
        System.out.println(arr);*/
    }
}

 

运行main方法测试

Array:size= 10 , capacity = 10 
[0,1,2,3,4,5,6,7,8,9]
Array:size= 11 , capacity = 20 
[0,100,1,2,3,4,5,6,7,8,9]
Array:size= 12 , capacity = 20 
[-1,0,100,1,2,3,4,5,6,7,8,9]

元素个数小于当前数组容积

//从数组中删除index位置的元素,返回删除的元素
    public E remove(int index){
        if(index < 0 || index >= size )
            throw new IllegalArgumentException("Set failed.Index is illegal.");

        E ret = data[index];
        for(int i = index + 1 ; i < size ; i ++){
            data[i-1] = data[i];
        }
        size --;
        data[size] = null;//loitering objects != memory leak

        //如果当前元素个数小于当前数组容积的一般
        if(size == data.length / 2)
            resize(data.length / 2);
        return ret;
    }

main方法

package com.practice;

import com.practice.Array.Array;

public class Main {

    public static void main(String[] args) {
    // write your code here
        Array<Integer> arr = new Array<Integer>();
        for(int i = 0 ; i < 10 ; i ++)
            arr.addLast(i);
        System.out.println(arr);

        arr.add(1,100);
        System.out.println(arr);

        arr.addFirst(-1);
        System.out.println(arr);



        arr.remove(2);
        System.out.println(arr);

        arr.removeElement(4);
        System.out.println(arr);

        arr.removeFirst();
        System.out.println(arr);
    }
}

main方法运行结果

Array:size= 10 , capacity = 10 
[0,1,2,3,4,5,6,7,8,9]
Array:size= 11 , capacity = 20 
[0,100,1,2,3,4,5,6,7,8,9]
Array:size= 12 , capacity = 20 
[-1,0,100,1,2,3,4,5,6,7,8,9]
Array:size= 11 , capacity = 20 
[-1,0,1,2,3,4,5,6,7,8,9]
Array:size= 10 , capacity = 10 
[-1,0,1,2,3,5,6,7,8,9]
Array:size= 9 , capacity = 10 
[0,1,2,3,5,6,7,8,9]

 

标签：arr,接上,--,System,println,Array,数据结构,out,size
来源： https://www.cnblogs.com/oneJavaWorkerStudy/p/16445971.html