Generates an array of integers of length 10, with each element in the array different (the range of values in the array is 1~20)

public static void Main (string[] args) {

Method one: Using the For loop
int arr[]=new int[10];
for (int i = 0; i < arr.length; i++) {
Arr[i]=r.nextint (20) +1;
for (int j = 0; J < i; J + +) {
if (Arr[i]==arr[j]) {
i--;
//}
//}
//}
System.out.println (arrays.tostring (arr));

Method two Set Set

hashset<integer> HashSet = new hashset<> ();

Random r = new Random ();
while (Hashset.size () < 10) {

Hashset.add (R.nextint (10));
System.out.println ("carried out");
}
System.out.println (HashSet);

}

Generates an array of integers of length 10, with each element in the array different (the range of values in the array is 1~20)