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