Java learning -HashSet practice

Create a string array length is 200
using random characters length is 2 to fill the string array
Statistics string array duplicate strings how many
use HashSet to solve this problem

 1 package Collection;
 2 
 3 import java.util.HashSet;
 4 
 5 public class HashSetTest {
 6     public static char randChar() { // 创建随机字符
 7         while (true) {
 8             char c = (char) (Math.round(Math.random() * 126));
 9             if (Character.isDigit(c) || Character.isLetter(c)) {
10                 return c;
11             }
12         }
13     }
14 
15     public static void print(String arr[]) { // 控制打印输出
16         for (int i = 0; i < arr.length; i++) {
17             if ((i + 1) % 20 == 0) {
18                 System.out.printf(arr[i] + "\n");
19             } else {
20                 System.out.printf(arr[i] + "\t");
21             }
22         }
23     }
24 
25     public static void main(String[] args) {
26          // Create random string array 
27          String ARR [] = new new String [200 is ];
 28          for ( int I = 0; I <arr.length; I ++ ) {
 29              ARR [I] = "" + randChar () + randChar ();
 30          }
 31 is          Print (ARR); // formatted print output 
32          HashSet <string> SET = new new HashSet <> (); // used to determine which string is repeated 
33 is          HashSet <string> = RES new new HashSet <> (); // used to store duplicate strings 
34 is          for (string S: ARR) {
 35             IF (set.add (S) == to false )
 36                  res.add (S);
 37 [          }
 38 is          System.out.printf ( "% d total one type of a repeating character string" , res.size ());
 39          the System. out.println ( "are: \ n-" + RES);
 40      }
 41 is }

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