Java算术运算符，请解释输出

Question

public class MainClass
{

     public static void main(String[] args)
     {
        int i = 13 - - 14 + + 15;
        // evaluate this as Right to Left associativity 
        // so (13 - (-14)) + + 15 = 27 + +15 = 42 --> correct 
        System.out.println(i);
     }
}

Since + and - has same precedence , so it will have right to left associativity. So I thought that any expression like 13 - - 14 + + 15 will be considered as 13 - (-14 + + 15) and output will be 12, but output is coming 42. Can anyone please explain the output?

Answer 1

您可以看到13 - - 14 + + 15就像13 - (-14) ，就像13 + 14等于27 ，其次是+ (+ 15)就像+ 15等于42。

Answer 2

如果从左至右（如Java一样）计算表达式，你下手13 - - 14这是一样的13 - (-14)这是27 27+ +15是42。

Answer 3

从左到右评估为13-（-14）+（+15），因此13 + 14 + 15 = 42