有没有更简单的方法来检查if语句中的一个值的多个值？ [英] Is there a simpler way to check multiple values against one value in an if-statement?

问题描述

基本上，我想要做的是检查一个给定值的两个整数，因此，通常你会做的是这样的：

Basically, what I want to do is check two integers against a given value, therefore, classically what you would do is something like this:

//just to get some values to check
int a, b;
a = (int)(Math.random()*5);
b = (int)(Math.random()*5);

//the actual thing in question
if(a == 0 || b == 0)
{
//Then do something
}

但是有更简洁的格式吗？可能与此类似（返回错误的操作数类型）：

But is there a more concise format to do this? Possibly similar to this (which returns a bad operand type):

//just to get some values to check
int a, b;
a = (int)(Math.random()*5);
b = (int)(Math.random()*5);

//the actual thing in question
if((a||b) == 0)
{
//Then do something
}

推荐答案

不幸的是，Java中没有这样的构造。

Unfortunately there is no such construct in Java.

在您的代码中经常进行这种比较，您可以实现一个小功能来执行检查：

It this kind of comparison is frequent in your code, you can implement a small function that will perform the check for you:

public boolean oneOfEquals(int a, int b, int expected) {
    return (a == expected) || (b == expected);
}

然后你就可以这样使用它：

Then you could use it like this:

if(oneOfEquals(a, b, 0)) {
    // ...
}

如果您不想将yourselft限制为整数，可以将上述函数设为通用：

If you don't want to restrict yourselft to integers, you can make the above function generic:

public <T> boolean oneOfEquals(T a, T b, T expected) {
    return a.equals(expected) || b.equals(expected);
}

请注意，在这种情况下，Java运行时将执行自动装箱和拆箱用于原始类型（如 int ），这是性能损失。

Note that in this case Java runtime will perform automatic boxing and unboxing for primitive types (like int), which is a performance loss.

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