为什么算术异常是未经检查的异常？

Question

有人可以解释为什么算术异常属于未检查的异常类别吗？我已经搜索了它，但没有正确的答案。如果有人回答，将不胜感激。

Answer 1

ArithmeticException extends RunttimeException , therefore it's unchecked.

Why this design decision? If ArithmeticException was checked, then you would have to encapsulate every (!) integer division in try catch or add a throws to the surrounding method.

The following program wouldn't compile:

class MyClass {
    int i = 10;
    void myMethod() {
        int j = 1 / i;
        // do something with j
    }
}

You would have to write either

void myMethod() throws ArithmeticException {
    int j = 1 / i;
    // do something with j
}

or

void myMethod() {
    int j;
    try {
        j = 1 / i;
    } catch (ArithmeticException e) {
        j = ...; // what value should be used?
    }
    // do something with j
}

At least to me, that would be very annoying.

Answer 2

为了使开发人员免于处理由于编程错误而导致的各种异常，例如从数组末尾掉落，除以零等等，因此将某些异常指定为未经检查的异常（这些异常源自RuntimeException ），并且不需要声明。

Answer 3

Because it's akin to an illegal argument exception.

All of IllegalArgumentException , IllegalStateException and NullPointerException are seen as programming errors and unchecked to avoid the excessive proliferation of throws clauses throughout code that in principle might throw any and all of those exceptions they're unchecked.

There's only a syntatic difference between:

y=a/b;

And

y=div(a,b);

Answer 4

Sounds like a old thread, but in case it helps, here are some detailed thoughts on the topic with more insights, reasoning & API references. FAQ about checked exception and unchecked exception?

Hopefully this will answer in more depth.