VDS Renaissance 的界面提供多种语言。官方文档以英语维护，以确保提供统一、一致且始终最新的参考。

@NULL

Syntax

@NULL(<string>)

Description

This function tests whether the enclosed string is empty. The value 1 (true) is returned if it is empty (null), otherwise the function returns null (false).

This function is equivalent to @NOT.

OK

Unchanged.

Example

IF @NULL(%2)
  WARN No command line parameter supplied!
END

See also

• @BOTH
• @EQUAL
• @NOT
• @ZERO