ArrayList与LinkedList各操作性能比较

超、凢脫俗 2022-03-11 01:54 220阅读 0赞

在数据量为50w的时候测试数据

@Test
    	public void array() {
    		
    		//ArrayList追加元素
    		long starttime = System.currentTimeMillis();
    		for (int i = 0; i < COUNT; i++) {
    			arrayList.add(i);
    		}
    		long endtime = System.currentTimeMillis();
    		System.out.println("ArrayList追加元素:"+(endtime - starttime));
    		
    		//初始化
    		arrayList = new ArrayList();
    		
    		//ArrayList插入元素
    		starttime = System.currentTimeMillis();
    		for (int i = 0; i < COUNT; i++) {
    			arrayList.add(0,i);
    		}
    		endtime = System.currentTimeMillis();
    		System.out.println("ArrayList插入元素:"+(endtime - starttime));
    		
    		//for循环遍历ArrayList
    		starttime = System.currentTimeMillis();
    		for (int i = 0; i < COUNT; i++) {
    			arrayList.get(i);
    		}
    		endtime = System.currentTimeMillis();
    		System.out.println("for循环遍历ArrayList:"+(endtime - starttime));
    		
    		//迭代器遍历ArrayList
    		starttime = System.currentTimeMillis();
    		Iterator i1 = arrayList.iterator();
    		Object obj1;
    		while(i1.hasNext()) {
    			obj1 = i1.next();
    		}
    		endtime = System.currentTimeMillis();
    		System.out.println("迭代器遍历ArrayList:"+(endtime - starttime));
    		
    	}
    	
    	@Test
    	public void linked() {
    		//LinkedList追加元素
    		long starttime = System.currentTimeMillis();
    		for (int i = 0; i < COUNT; i++) {
    			linkedList.add(i);
    		}
    		long endtime = System.currentTimeMillis();
    		System.out.println("LinkedList追加元素:"+(endtime - starttime));
    		
    		//初始化
    		linkedList = new LinkedList();
    		
    		//LinkedList插入元素
    		starttime = System.currentTimeMillis();
    		for (int i = 0; i < COUNT; i++) {
    			linkedList.add(0,i);
    		}
    		endtime = System.currentTimeMillis();
    		System.out.println("LinkedList插入元素:"+(endtime - starttime));
    		
    		//for循环遍历LinkedList
    		starttime = System.currentTimeMillis();
    		for (int i = 0; i < COUNT; i++) {
    			linkedList.get(i);
    		}
    		endtime = System.currentTimeMillis();
    		System.out.println("for循环遍历LinkedList:"+(endtime - starttime));
    		
    		//迭代器遍历LinkedList
    		starttime = System.currentTimeMillis();
    		Iterator i2 = linkedList.iterator();
    		Object obj2;
    		while(i2.hasNext()) {
    			obj2 = i2.next();
    		}
    		endtime = System.currentTimeMillis();
    		System.out.println("迭代器遍历LinkedList:"+(endtime - starttime));
    	}

![20190306230846375.png][]    ![20190306231436880.png][]

可以看出在进行追加（有序添加）、遍历的时候ArrayList的效率高于LinkedList，但是在无序插入的时候LinkedList效率高于ArrayList。

在做其余数据量测试的时候得出ArrayList通过for循环遍历效率要高于迭代器遍历，LinkedList迭代器遍历效率要远高于for循环遍历。

[20190306230846375.png]: https://img-blog.csdnimg.cn/20190306230846375.png
[20190306231436880.png]: /images/20220311/59e6683978aa4c609d118a4cebe1ec2e.png