Java arbitrary set of randomly generated telephone numbers

| - demand explanation

Required according to user input, generating a phone number corresponding the number of groups

 

| - realization of ideas

1, through Baidu, access to the corresponding first three digits of the phone number in the real world

2, using Math.random () method, generates eight digits of a phone number

 

| - Content Code 

. 1  Package com.work;
 2  
. 3  Import java.util.Scanner;
 . 4  
. 5  / ** 
. 6  * 9527 :: @auther
 . 7  * @Description: randomly generated telephone number
 . 8  * @program: shi_yong
 . 9  * @Create: 2019-07 10:22 -30
 10   * / 
. 11  public  class RandomPhoneNum {
 12 is      static Scanner SC = new new Scanner (the System.in);
 13 is  
14      public  static <lenPhone> void main (String [] args) {
 15          // query requires random number number 
16          boolean= Boo to true ;
 . 17          int NUM = 0 ;
 18 is          do {
 . 19              // If the user input is not an integer, it requires the user to enter an integer loop 
20 is              System.out.println ( "How much do you need phone number, enter an integer " );
 21 is              String answer = sc.next ();
 22 is              the try {
 23 is                  // user's input integer into 
24                  NUM = the Integer.parseInt (answer);
 25                  // If the conversion is successful, boo it is set to false may be out of the loop 
26 is                  Boo = to false ;
 27              } the catch (Exception E) {
28                  // if user input is not an integer, throwing an exception, requiring the user to re-enter 
29                  System.out.println ( "Your input is not an integer, please re-enter" );
 30              }
 31  
32          } the while (Boo) ;
 33 is  
34 is          System.out.println ( "want your phone number as follows:" );
 35          // to set the number of cycles required by the user number 
36          for ( int I = 0; I <NUM; I ++ ) {
 37 [              // static method call generated phone number 
38 is              getPhoneNum ();
 39          }
 40      }
 41 is  
42 is      // a given static method, generating a single special number 
43     public  static  void getPhoneNum () {
 44 is          // given real number initial segment, segment number is looked up in the above Baidu real number section 
45          String [] = {Start "133", "149", "153", "173" , "177" ,
 46                  , "180", "181", "189", "199", "130", "131", "132" ,
 47                  , "145", "155", "156", "166" , "171", "175", "176", "185", "186", "166", "134", "135" ,
 48                  , "136", "137", "138", "139", "147", "150","151", "152", "157", "158", "159", "172" ,
 49                  , "178", "182", "183", "184", "187", "188", " 198 "," 170 "," 171 " };
 50  
51 is          // random real number section illustrating the use of an array length property, to obtain the array length,
52          // by Math.random () * the array length to obtain the array index, the random number so that the top three segments 
53 is          String Start phoneFirstNum = [( int ) (Math.random () * start.length)];
 54 is          // the remaining 8 bits out of random 
55          String phoneLastNum = "" ;
 56 is          // define tail number, an 8-bit tail number 
57 is          Final  int LENPHONE 8 = ;
 58          // cycle remaining bits 
59          for ( int I = 0 ; I <LENPHONE; I ++ ) {
 60              // each cycle selected from 0 to 9, a random number 
61 is              phoneLastNum + = ( int ) (Math.random () * 10 );
62          }
 63          // final mantissa and the number of segments joined 
64          String phoneNum + = phoneFirstNum phoneLastNum;
 65          System.out.println (phoneNum);
 66      }
 67 }

Any desired number of randomly generated telephone number

 

 | - operating results