VBA:&和+ [英] VBA: Difference between & and +

问题描述

两者之间有什么区别

string1 + string2

和

string1 & string2

它们等效吗?为什么会有两个不同的符号执行相同的操作?

Are they equivalent? Why have two different symbols that do the same thing?

推荐答案

只要操作数是字符串，表达式是相同的；如果不是，则+可能会添加它们，具体取决于类型转换. &保证除了字符串连接外不会得到任何东西，并且会尽可能将操作数转换为字符串.

The expressions are the same as long as the operands are strings; if not, + might add them instead depending on type conversions. & guarantees you won't get anything except a string concatenation, and will convert operands to strings if possible to do so.

有一个有关 Visual Basic中的串联操作的MSDN条目对此进行了解释:

There's an MSDN entry about Concatenation operations in Visual Basic that explains it:

&运算符(Visual Basic)仅为String操作数定义，并且无论Option Strict的设置如何，它始终将其操作数扩展为String. &建议您将运算符用于字符串连接，因为该操作符是专门为字符串定义的，可减少生成意外转换的机会.

The & Operator (Visual Basic) is defined only for String operands, and it always widens its operands to String, regardless of the setting of Option Strict. The & operator is recommended for string concatenation because it is defined exclusively for strings and reduces your chances of generating an unintended conversion.

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