Java Fundamentals Hardening 82:math Class Random () method to obtain arbitrary range of randomly-number cases (interview questions)

1. Requirements: Design a method that can achieve random numbers in any range

Analysis: How to use random () is as follows:

  1      Public Static Double random () 2 Note: 0.0 (inclusive) 1.0 (Exclusive).        //0.0 <= x <1.0

(1) keyboard input two number.

1    int start; 2    int  End

(2) Find a way to get the random number between start and end

(3) Output this random number

2. Code implementation:

1  Packagecn.itcast_02;2 3 ImportJava.util.Scanner;4 5 /*6 * Requirements: Please design a method that can achieve random numbers in any range. 7  * 8 * Analysis:9 * A: Keyboard input two data. Ten * int strat; One * int end; A * B: Find a way to get the random number between start and end - * I write a function to achieve this effect and get a random number. (int) - * C: Output This random number the  */ -  Public classMathdemo { -      Public Static voidMain (string[] args) { -Scanner sc =NewScanner (system.in); +System.out.println ("Please enter start number:"); -         intStart =sc.nextint (); +System.out.println ("Please enter end number:"); A         intEnd =sc.nextint (); at  -          for(intx = 0; x < 100; X + +) { -             //Invoke function -             intnum =getrandom (start, end); -             //Output Results - System.out.println (num); in         } -     } to  +     /* - * Write a function two explicit: return value type: int argument list: int Start,int end the      */ *      Public Static intGetrandom (intStartintend) { $      //think back to the random numbers we talked about between 1-100.Panax Notoginseng      //int number = (int) (Math.random () * +) + 1;//(int) (Math.random () *100)-- 0 <= x <100, then (math.random () *100+1)-- 1<=x<101  -      //int number = (int) (Math.random () * end) + start; the         //found a problem, how to do it? +         intNumber = (int) (Math.random () * (End-start + 1)) +start;// start <= x <= End  A         returnNumber ; the     } +}

The results are as follows:

Java Fundamentals Hardening 82:math Class Random () method to obtain arbitrary range of randomly-number cases (interview questions)