📅  最后修改于: 2022-03-11 14:58:25.978000             🧑  作者: Mango
%ifvar%
You use the %ifvar% tag to conditionally include or exclude a block of code based on the existence or value of a specified variable.
Syntax
%ifvar Variable [option option
option...]%
Block of Code
[%else%
Block of Code]
%end%