Collection类及常用API
Collection—类集工具类,定义了若干用于类集和映射的算法,这些算法被定义为静态方法,具体查看api文档;
a) public static void sort(List<T> liet)
b) public static int binarySearch(List<T> list,T key)
c) public static void reverse(List<?> list)
d) public static void shuffle(List<?> list)
e) public static void swap(List<?> list,int i,int j)
f) public static <T> void fill(List<? super T> list,T obj)
1 List<String> nList=new ArrayList<String>(); 2 nList.add("zhangsan"); 3 nList.add("lisi"); 4 nList.add("wangwu"); 5 nList.add("zhaoliu"); 6 nList.add("tianqi"); 7 System.out.println("操作前"); 8 for(String s:nList){ 9 System.out.print(s+" ");10 }11 12 System.out.println();13 System.out.println("交换顺序后");14 Collections.swap(nList,1,2);15 for(String s:nList){16 System.out.print(s+" ");17 }18 19 System.out.println();20 System.out.println("自然排序后");21 Collections.sort(nList);22 for(String s:nList){23 System.out.print(s+" ");24 }25 26 System.out.println();27 System.out.println("二分法查找");28 System.out.println(Collections.binarySearch(nList, "zhaoliu"));29 30 System.out.println("打乱顺序");31 Collections.shuffle(nList);32 for(String s:nList){33 System.out.print(s+" ");34 }35 36 System.out.println();37 System.out.println("填充");38 Collections.fill(nList, "jay");39 for(String s:nList){40 System.out.print(s+" ");41 }
输出结果:
操作前
zhangsan lisi wangwu zhaoliu tianqi
交换顺序后
zhangsan wangwu lisi zhaoliu tianqi
自然排序后
lisi tianqi wangwu zhangsan zhaoliu
二分法查找
4
打乱顺序
zhaoliu tianqi wangwu zhangsan lisi
填充
jay jay jay jay jay
原标题:Collection类及常用API
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