java - 表达式包含 "at most one side effect, as its outermost operation"是什么意思？

Question

在Java Language Spex 15.7 :

Code is usually clearer when each expression contains at most one side effect, as its outermost operation

这是什么意思？

Answer 1

这意味着每个表达式应该一次完成一个任务。

考虑以下两个声明:

int a = 10;
int b = 20;

现在的任务是将这两个int相加并将b递增1。有两种方法可以做到。

int c = a + b++;

和

int c = a + b;
b++;

JLS更喜欢并推荐后者。