Kotlin检查了例外情况

Question

Since Kotlin doesn't support checked exceptions then how to make a programmer aware that a method may throw exception

Simple example:

class Calculator (value: Int = 0) {

    fun divide (dividend: BigDecimal, divider: BigDecimal) : BigDecimal {
        return dividend / divider
    }
}

Obviously the divide method may throw java.lang.ArithmeticException: Division by zero exception and the creator of the library needs to warn the user of the class to put the invoke in a try-catch clause

What's the mechanism for that awareness in Kotlin?

Answer 1

Given the fact that the language doesn't have a construct to make this explicit, the only thing left is: implicitly.

For example by putting javadoc that clearly tells the user of the method about what/why exceptions might be thrown at him. Or you use the @Throws annotation.

Maybe, maybe the kotlin team will add compiler warnings at some point to make up for this ( see here ).

Answer 2

You can return Try so that client can call isSuccess or isFailure http://www.java-allandsundry.com/2017/12/kotlin-try-type-for-functional.html

You can also return nullable type BigDecimal? so that client will know that the value might not exist (when divided by zero you can return null).