Java如何返回两个变量？
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Java how to return two variables?
提问by UniQuadrion
after c++ i am trying to learn some java, and i have a question about the code i have been working on. I am working on a Fraction class and i got stuck in reduce section. Since the method did not let me to return both "num" and "den", I had to return "n" This is my method
在 C++ 之后，我正在尝试学习一些 Java，并且我对我一直在研究的代码有疑问。我正在学习分数课程，但我陷入了减少部分。由于该方法不允许我同时返回“num”和“den”，我不得不返回“n”这是我的方法
public double reduce() {
int n = num;
int d = den;
while (d != 0) {
int t = d;
d = n % d;
n = t;
}
int gcd = n;
num /= gcd; //num = num / greatestCommonDivisor
den /= gcd; //den = den / greatestCommonDivisor
return n;
}
I am trying to do "return num, den;" however it does not let me.
我正在尝试“返回 num，den；” 但是它不允许我。
and this is what i get
这就是我得到的
to reduced test for 100/2 is 2.0
to reduced test for 6/2 is 2.0
when i run
当我跑步时
System.out.println("to reduced test for " + f4.toString() + " is " + f4.reduce());
System.out.println("to reduced test for " + f6.toString() + " is " +f6.reduce());
Why do i get the 2 when when i am supposed to get 50/1 and 3/1 ? If the IDE let me return num and den at the same time, would that have fixed it?
为什么我应该得到 50/1 和 3/1 时得到 2？如果 IDE 让我同时返回 num 和 den，那会解决它吗？
Thanks
谢谢
采纳答案by Martijn Courteaux
Java has no native way of doing this, you only can return one Objector primitive. This leaves you two options:
Java 没有这样做的本地方式，您只能返回一个Object或原语。这给您留下了两个选择：
Return an array with length 2.
public int[] reduce() { ... return new int[]{num, den}; }Return an object of a wrapper class containing the two numbers.
public Fraction reduce() { ... return new Fraction(num, den); }
返回一个长度为 2 的数组。
public int[] reduce() { ... return new int[]{num, den}; }返回包含两个数字的包装类的对象。
public Fraction reduce() { ... return new Fraction(num, den); }
回答by rgettman
It looks like your reducemethod is modifying the object. It's unclear what exactly you want to return. If you want the fraction to return itself, then return this;, with the method returning a Fractionin the declaration.
看起来您的reduce方法正在修改对象。目前还不清楚你到底想返回什么。如果您希望分数返回自身，则return this;，该方法Fraction在声明中返回 a 。
