有理數類

類的成員變數

任何一個有理數都可以用分數進行表示，所以有理數類的成員應該包含兩個：

     int numerator = 1;//分子
     int denominator = 1;//分母

無參構造與傳參構造

public Rational() {
    }

    ;//無參構造

    public Rational(int numerator, int denominator) {
        this.numerator = numerator;
        this.denominator = denominator;
    }

get set 函式

public int getNumerator() {
        return numerator;
    }

    public int getDenominator() {
        return denominator;
    }

    public void setNumerator(int numerator) {
        this.numerator = numerator;
    }

    public void setDenominator(int denominator) {
        this.denominator = denominator;
    }
 

類的方法

有理數重要的運算：四則運算

 //四則運算
    Rational add(Rational a) {
        Rational c = new Rational();

        c.denominator = this.denominator * a.denominator;
        c.numerator = this.denominator * a.numerator + this.numerator * a.denominator;
        return c;
    }

    Rational sub(Rational a) {
        Rational c = new Rational();

        c.denominator = this.denominator * a.denominator;
        c.numerator = this.denominator * a.numerator - this.numerator * a.denominator;
        return c;
    }

    Rational mult(Rational a) {
        Rational c = new Rational();

        c.denominator = this.denominator * a.denominator;
        c.numerator = this.numerator * a.numerator;
        return c;
    }

    Rational div(Rational a) {
        Rational c = new Rational();

        c.denominator = this.denominator * a.denominator;
        c.numerator = this.numerator * a.denominator;
        return c;
    }

    public String toString() {
        return ("分母是:" + numerator + " 分子是:" + denominator);
    }
 

轉化位小數方法

 //得值
    public double doubleVaule() {
        return numerator * 1.0 / denominator * 1.0;
    }

equals比較方法

public boolean equals(Rational a) {
        if ((a.getDenominator() == this.denominator) && (a.getNumerator() == this.numerator))
            return true;
        else
            return false;
    }
}
 

列印分母、分子的值

public String toString() {
        return ("分母是:" + numerator + " 分子是:" + denominator);
    }

測試分析

Test進行測試

public class Test {
    public static void main(String[] args) {
        Rational r =new Rational(3,4);
        Rational r2=new Rational(1,2);
        System.out.println(r.add(r2));
        System.out.println(r.div(r2));
        System.out.println(r.mult(r2));
        System.out.println(r.sub(r2));
        System.out.println(r.equals(r2));
        System.out.println(r.doubleVaule());
        System.out.println(r2.doubleVaule());
        System.out.println(r);
        System.out.println(r2);
    }
}

結果展示