Java中Arrays 与 Collections 的简单操作

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;


public class Test{


	
		
	public static void main(String[] args) {
		
		/*
		 * Arrays 提供了很多对数组操作的函数
		 * 这里只演示几个常用功能呢个
		 */
		
		System.out.println("-----------Arrays--------------");
		String[] s = new String[10];
		Arrays.fill(s, "a");
		System.out.println("Arrays.fill :  " + Arrays.deepToString(s));
		s = new String[]{"Jone","tom", "jerry"};
		System.out.println("Arrays.deepToString : " + Arrays.deepToString(s));
		Arrays.sort(s);
		System.out.println("Arrays.sort : " + Arrays.deepToString(s));
		System.out.println("Arrays.binarySearch : " + Arrays.binarySearch(s, "jerry"));
	
		/*
		 * Collections 提供了很多对集合操作的函数
		 * 这里只演示几个常用功能呢个
		 */
		System.out.println("-----------Collections--------------");
		List<String> s1 = new ArrayList<String>();
		Collections.fill(s1, "bb");
		System.out.println("Collections.fill bb : " + s1);
		s1.add("Jone"); s1.add("tom");  s1.add("jerry"); 
		Collections.fill(s1, "cc");
		System.out.println("Collections.fill bb : " + s1);  //只能替换已存在的
		s1.clear();
		s1.add("Jone"); s1.add("tom");  s1.add("jerry"); 
		System.out.println(s1);
		
		Collections.sort(s1);
		System.out.println("Collections.sort : " + s1);
		System.out.println("Collections.binarySearch : " + Collections.binarySearch(s1, "jerry"));
		
		System.out.println("Collections.max : " + Collections.max(s1) + "Collections.min :" + Collections.min(s1));
	}

}

输出:
-----------Arrays--------------
Arrays.fill :  [a, a, a, a, a, a, a, a, a, a]
Arrays.deepToString : [Jone, tom, jerry]
Arrays.sort : [Jone, jerry, tom]
Arrays.binarySearch : 1
-----------Collections--------------
Collections.fill bb : []
Collections.fill bb : [cc, cc, cc]
[Jone, tom, jerry]
Collections.sort : [Jone, jerry, tom]
Collections.binarySearch : 1
Collections.max : tomCollections.min :Jone

  

原文地址:https://www.cnblogs.com/E-star/p/3441169.html