修復了我自己的If-Else語句

Question

所以我是一名學習Java的學生。我目前正在忙於一項任務，但我一直陷入一些if-else邏輯。

我的任務要求我寫一個有理數（如72/14）的類文件，顯示它，將其分解成最低的形式（在這種情況下是36/7），將有理數作爲價值，最後顯示最大的共同因素。我遇到的問題是，我的代碼沒有篩選出這樣一個事實：例如，72/13是理性數字可以變得最小的事實，但是我知道它不會崩潰，而是反過來我把它換成了72/14的值搜索，並且這樣不能正常工作。

我的代碼：

public class QTwoAssiThree 
{ 
    private int numerator; 
    private int denominator; 

    public void writeOutput() 
    { 
     if (getGCD(numerator, denominator) >= 2) 
     { 
      System.out.println(toString() + " is the simplified rational number."); 
      System.out.println(getValue() + " is the value of the two rational numbers as one number."); 
      System.out.println((getGCD(numerator, denominator) * 2) + " is the largest common factor."); 
     } 
     else if (getGCD(numerator, denominator) == 1) 
     { 
      System.out.println(getValue() + " is the value of the two rational numbers as one number."); 
      System.exit(0); 
     }  
    } 
    public QTwoAssiThree() 
    { 
     numerator = 0; 
     denominator = 0; 
    } 
    public QTwoAssiThree(int initialNum, int initialDenom) 
    { 
     if (denominator % 2 == 0) 
     { 
      numerator = initialNum; 
      if (initialDenom > 0) 
      { 
       denominator = initialDenom; 
       System.out.println(toString() + " is the rational number entered."); 
       simplify(numerator, denominator); 
      } 
      else 
      { 
       System.out.println("Invalid value added as the denominator! Only positive integers should be used."); 
       System.exit(0); 
      } 
     } 
     else if (denominator % 2 == 1) 
     { 
      System.out.println(toString() + " is what was entered, and is already in its simplest form."); 
     } 
    } 
    private void simplify(int newNum, int newDenom) 
    { 
     numerator = newNum/getGCD(newNum, newDenom); 
     denominator = newDenom/getGCD(newNum, newDenom); 
    } 
    private static int getGCD(int x, int y) 
    { 
     int difference = x % y; 

     return difference; 
    } 
    private double getValue() 
    { 
     double doubleValue = (double)numerator/(double)denominator; 

     return doubleValue; 
    } 
    public String toString() 
    { 
     String fraction = Integer.toString(numerator) + "/" + Integer.toString(denominator); 

     return fraction; 
    } 
} 

現在，請忽略的事實是，我依然對知識的Java程序員規模偏低。我很感激任何關於此的指針，因爲我陷入困境，無法真正弄清楚如何設置它。有兩個地方我使用if-else來查看它是否有效，第一個地址是： public void writeOutput()和public QTwoAssiThree(int initialNum, int initialDenom)構造函數。最初沒有任何if-else陳述，但代碼確實工作，但不適用於不均勻的整數。

public class QTwoAssiThreeDemo 
{ 
    public static void main(String[] args) 
    { 
     QTwoAssiThree rationalNumbers = new QTwoAssiThree(72, 14); 

     rationalNumbers.writeOutput(); 
    } 
} 

是用來演示整個班級。

我的產出應該是基本上什麼樣的情況如下：

72/14 is the rational number entered. 
    36/7 is the simplified rational number. 
    5.142857143 is the value of the two rational numbers as one number. 
    2 is the largest common factor. 

和

72/13 is what was entered, and is already in its simplest form. 
    5.538461538 is the value of the two rational numbers as one number. 

的代碼進行優化，在長相醜陋，我知道，但任何幫助，將不勝感激，我會在我提交作業之前，先做好一切工作，讓它看起來更漂亮些。

Answer 1

代碼，需要改變（IMO）：

1. 構造必須只能用來初始化對象
2. 改變的GCD功能繼refered鏈接
3. 您可以添加的內部構造的簡化功能（因爲它重新初始化了這些值）
4. 使用try和catch塊來檢查它們是否是有效的輸入否則拋出Exceptions

更改的程式碼：

public class QTwoAssiThree { 
    private int numerator; 
    private int denominator; 

    public void writeOutput() { 

     System.out.println(toString() + " is the rational number entered."); 
     if (simplify(numerator, denominator)>1) 
      System.out.println(toString()+ " is the simplified rational number."); 
     else 
      System.out.println(toString()+ " is what was entered, and is already in its simplest form."); 
     System.out .println(getValue() +" is the value of the two rational numbers as one number."); 
    } 

    public QTwoAssiThree() { 
     numerator = 0; 
     denominator = 0; 
    } 

    public QTwoAssiThree(int initialNum, int initialDenom) { 

     numerator = initialNum; 
     denominator = initialDenom; 
     if (initialDenom <= 0) { 
      System.out 
        .println("Invalid value added as the denominator! Only positive integers should be used."); 
      System.exit(0); 
     } 
    } 

    private int simplify(int newNum, int newDenom) { 
     int gcd = getGCD(newNum, newDenom); 
     numerator = newNum/gcd; 
     denominator = newDenom/gcd; 
     return gcd; 
    } 

    private static int getGCD(int x, int y) { 

     if (y == 0) { 
      return x; 
     } 
     return getGCD(y, x % y); 
    } 

    private double getValue() { 
     double doubleValue = (double) numerator/(double) denominator; 

     return doubleValue; 
    } 

    public String toString() { 
     String fraction = Integer.toString(numerator) + "/" 
       + Integer.toString(denominator); 

     return fraction; 
    } 
}