为什么一元运算符具有关联性

Question

在像＆＃34; 10 - 3 - 2＆＃34;这样的表达式中，很容易理解为什么 - 和+运算符是关联的。为了匹配数学约定，结果有5而不是9。据我所知，关联性是指某些运算符具有相同优先级时的顺序。

但这与一元运营商有什么相关性？我不明白为什么一元运算符具有相关性。

注意：问题是关于一般编程，但如果你必须以语言相关的方式回答，C是首选。

Answer 1

**Arithmetic Operators** (Left-to-Right)
+   Additive operator (a + b)
-   Subtraction operator (a - b)
*   Multiplication operator (a * b)
/   Division operator (a / b)
%   Remainder operator (a % b)

**Unary operators** (Right-to-Left)
+   Unary plus operator; indicates positive value (numbers are positive without this, however) 
-   Unary minus operator; negates an expression
++  Increment operator; increments a value by 1
--  Decrement operator; decrements a value by 1
!   Logical complement operator; inverts the value of a boolean

但是当我们考虑一元时，例如：

a = +1
a= -1
a++
a-- etc

您在此处提到10 - 3 - 2的内容将不会被纳入一元操作。

So the operation will be Left-to-Right. Therefore:
10 - 3 equals 7 then
7 - 2 equals 5

Not as given below (Arithmetic operators always Left-to-Right not Right-to-Left)
3 - 2 = 1 then
10 - 1 = 9 This is absolutely wrong.

有关详细信息，请查看以下参考：

  

  
1. Precedence and Associativity
  
2. Assignment, Arithmetic, and Unary Operators（我与C语言的联系并不多。但运营商很常见。）