如何在Delphi中定义空字符 [英] How to define Empty Char in Delphi
问题描述
出于好奇,
为什么在Delphi中,如果我们通过以下方式定义空字符:
Why in Delp if we defined an empty char by:
a:Char;
a:='';
我们得到一个错误:不兼容的类型:'Char'和'string'
但是,如果我们放置
a:='a';
会很好吗?
是有必要通过以下方式定义一个空字符: a:=#0
?
Is it necessary to define an empty char by: a:=#0
?
推荐答案
字符是一个(即正好一个)字符。因此, a,∫和⌬都可以,但 ab(两个字符的字符串), Hello World!(十二个字符的字符串)或(零个字符,
A char is a single (that is, exactly one) character. So 'a', '∫', and '⌬' are all OK, but not 'ab' (a two-character string), 'Hello World!' (a twelve-character string), or '' (a zero-character string).
但是,NULL字符(#0)则与其他字符相同。
However, the NULL character (#0) is a character like any other.
此外,字符数据类型被实现为一个单词(在现代版本的Delphi中),即两个字节。如果所有这些值0、1,...,2 ^ 16-1都用于实字符,那么您在世界上将如何表示空字符?
In addition, the character datatype is implemented as a word (in modern versions of Delphi), that is, as two bytes. If all these values 0, 1, ..., 2^16 - 1 are used for real characters, how in the world would you represent your 'empty char'?
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