集合类

Array

int[] anArray = new int[10];  
int[] int_array =  { 1, 2, 3 };  

String[] str_array = new String[3];  
String[] str_array2 = new String[] { "A", "B", "C" };

// fill
long[] long_array = new long[5];  
Arrays.fill(long_array, 30);  

int[] int_array2 = new int[5];  
Arrays.fill(int_array2, 0, 3, -50);  

/// copy
int[] int_array3 = {1,2,3,4,5};  
int[] copy = Arrays.copyOf(int_array3, 5);  
  
// sort
int[] needSort = new int[] {10,-2,3,-14,5};  
Arrays.sort(needSort);  
  
String[] needSortString = new String[] {"A", "E", "Z", "B", "C"};  
Arrays.sort(needSortString, 1, 3, Comparator  
        .comparing(String::toString)  
        .reversed());  

// search
int[] binArray = new int[] {1,2,3,4,5};  
int index = Arrays.binarySearch(binArray, 4);

List

List<Integer> aList = Arrays.asList(array); 

List<String> cities = new ArrayList() {{ 
	add("New York"); 
	add("Rio"); 
	add("Tokyo"); 
}};

Set

Set<String> set = Set.of("India", "USSR", "USA");