C# 语言特性系列(10) 深入理解默认值 Default Values

The following categories of variables are automatically initialized to their default values:

  • Static variables.
  • Instance variables of class instances.
  • Array elements.

The default value of a variable depends on the type of the variable and is determined as follows:

  • For a variable of a value-type, the default value is the same as the value computed by the value-type's default constructor.
  • For a variable of a reference-type, the default value is null.

Initialization to default values is typically done by having the memory manager or garbage collector initialize memory to all-bits-zero before it is allocated for use. For this reason, it is convenient to use all-bits-zero to represent the null reference.

posted @ 2008-10-09 10:39  许晓光  阅读(514)  评论(0编辑  收藏  举报