asp 空值测试判断函数

'函数：空值测试
function inull(val)
dim tmp
tmp = false
if isnull(val) then
tmp = true
elseif isempty(val) then
tmp = true
elseif trim(val) = "" then
tmp = true
end if
inull = tmp
end function

测试变量是否为空值，空值的含义包括：变量不存在/为空，对象为nothing，0，空数组，字符串为空
function isblank(byref var)
isblank = false
select case true
case isobject(var)
if var is nothing then isblank = true
case isempty(var), isnull(var)
isblank = true
case isarray(var)
if ubound(var) = 0 then isblank = true
case isnumeric(var)
if (var = 0) then isblank = true
case else
if trim(var) = "" then isblank = true
end select
end function