JAVA几个collection框架

Posted 2021-01-25 ulyssescat

• Arrays

public static void main(String[] args) {
        //binarySearch,注意二分查找要求数组有序
        int[] nums1 = {2,4,6,8,10};
        Arrays.binarySearch(nums1, 1);//返回-1
        Arrays.binarySearch(nums1, 8);//返回3
        
        //copyOf,截取or用0填充，该拷贝不影响原来的数组
        int[] nums2 = Arrays.copyOf(nums1, 3);
        
        //copyOfRange,一定范围内截取
        int[] nums3 = Arrays.copyOfRange(nums1, 2, 10);
        
        //fill,填充+范围填充
        Arrays.fill(nums3, 0);
        Arrays.fill(nums3, 0, 4, 0);
        
        //sort,排序
        int[] nums4 = {2,4,10,8,6};
        Arrays.sort(nums4);
    }

• HashMap<K,V>
• (TODO)