如何在一个类中循环所有方法和对象？ （Java）的

Question

I need to loop every method inside my class RandomMath

I'm trying to implement an algorithm which:

1. generates a 4 digit number.
2. rearranges the digits into the largest arrangements creating a new value called bigger.
3. does the same but into the smallest arrangement creating a new value called smaller.
4. subtracts smaller from bigger to make a new 4 digit number called new4Digit
5. loop the process from step 2 ten times using new4Digit obtained above instead of generating a new number.

I've already done steps 1-4 as well as implement a statement which makes the process replace the generated number with new4Digit after the first run of the process. Now I need to essentially loop the entire class and it will be done. Anyone know how?

my code:

import java.util.Random;


public class RandomMath {

    private static int generated = generator();
    //first set of values for the bigger, smaller and new 4 digit numbers
    final private static int bigger = bigger();
    final private static int smaller = smaller();
    final private static int new4Digit = subtraction();
    public static void main(String[] args) {
        System.out.println(bigger);
        System.out.println(smaller);
        System.out.println(new4Digit);
    }
    //create method for generating random numbers
    public static int generator(){
        int n = 0;
        //new4Digit is initialised to zero. So after the first loop instead... 
        //...of generating a new number the value of n is taken as new4Digit 
        if(new4Digit != 0){
            n = new4Digit;
        }
        else{
        Random randomGen = new Random();
        //set max int to 10000 as generator works between 0 and n-1
        for(int i=0; i<1; i++){
            n = randomGen.nextInt(10000);
            if((n==1111 || n==2222 || n==3333 || n ==4444 || n==5555)
                      ||(n==6666 || n==7777 || n==8888 || n==9999 || n==0000)){
                 i--;
            }
        }
        }
        return n;
    }
    //method for denoting the bigger number
    public static int bigger(){
        int[] times = new int[10];
        while (generated != 0) {    
            int digit = generated % 10;
            times[digit]++;
            generated /= 10;
        }
        int big = 0;
        for (int i = 9; i >= 0; i--) {
            for (int j = 0; j < times[i]; j++) {
                big = big * 10 + i;
            }
        }
        //code below accounts for ints with leading zeroes
        //if the numer has three leading zeroes (<10) times by 1000
        if (big < 10){
            big = big * 1000;
        }
        //if the number has two leading zeroes (<100) times by 100
        else if(big < 100){
            big = big * 100;
        } 
        //if the number has one leading zero (<1000) times by 10
        else if(big < 1000){
            big = big * 10;
        }
        return big;
    }
    //denoting the smaller number by simply reversing the bigger
    public static int smaller(){
        int d1 = bigger %10;
        int r1 = bigger /10;
        int d2 = r1 % 10;
        int r2 = r1 / 10;
        int d3 = r2 % 10;
        int r3 = r2 / 10;
        int d4 = r3 % 10;

        int small = d1 * 1000 + d2 * 100 + d3 * 10 + d4;
        return small;
    }
    //method for subtracting the smaller number from the bigger
    public static int subtraction(){
        int newNumber = bigger - smaller;
        return newNumber;
    }

}

Answer 1

Don't use static methods. Create an object/class with constructor, methods, parameters and fields and call methods you need several times on a instance of this class

Answer 2

If I understand your question, you should use something this (instead of static fields use parameters):

import java.util.Random;


public class RandomMath {

    public static void main(String[] args) {
        int new4Digit = loop(10);
        System.out.println(new4Digit);
    }

    public static int loop(int times){
        int new4Digit = 0;
        for(int i=0; i< times; i++) {
            new4Digit = generator(new4Digit);
            new4Digit = subtraction(new4Digit);
        }
        return new4Digit;
    }

    //create method for generating random numbers
    public static int generator(int new4Digit){
        ...
        return n;
    }
    //method for denoting the bigger number
    public static int bigger(int generated){
        ...
        return big;
    }
    //denoting the smaller number by simply reversing the bigger
    public static int smaller(int bigger){
        ...
        return small;
    }
    //method for subtracting the smaller number from the bigger
    public static int subtraction(int generated){
        int bigger  =  bigger(generated);
        int newNumber = bigger - smaller(bigger);
        return newNumber;
    }
}