问题描述
我知道这样的话题被问了好几次，但我的问题是关于完整的 32 位 int 的溢出.例如:
I know such topic was asked several times, but my question is about overflow on full 32 bits of int. For example:
11111111111111111111111111111111 +
00000000000000000000000000000001 =
00000000000000000000000000000000 //overflow!
我发现 topic 有类似的问题，但是算法并不完美.
I found topic with similar question about this, however the algorithm is not perfect.
11111111111111111111111111111111 +
00000000000000000000000000000000 =
00000000000000000000000000000000 //overflow!
有没有什么简单、快速、安全的检查方法?
Is there any simple, fast, safer way to check this ?
推荐答案
Math.addExact 溢出时抛出异常
从 Java 8 开始，数学类:
Math.addExact throws exception on overflow
Since Java 8 there is a set of methods in the Math class:
toIntExact(long)addExact(int,int)subtractExact(int,int)multiplyExact(int,int)
……以及长期版本.
这些方法中的每一个都会抛出 ArithmeticException 如果发生溢出.否则，如果它在范围内，它们会返回正确的结果.
Each of these methods throws ArithmeticException if overflow happens. Otherwise they return the proper result if it fits within the range.
加法示例:
int x = 2_000_000_000;
int y = 1_000_000_000;
try {
int result = Math.addExact(x, y);
System.out.println("The proper result is " + result);
} catch(ArithmeticException e) {
System.out.println("Sorry, " + e);
}
查看此在 IdeOne.com 上实时运行的代码.
对不起，java.lang.ArithmeticException:整数溢出
Sorry, java.lang.ArithmeticException: integer overflow
这篇关于如何检测 32 位 int 上的整数溢出?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！