检测整数与长整数的函数

经常见到cint和clng的溢出出错，如果有检测函数就不会出这个问题，下面这两个函数是应朋友要求写的，看一下吧

'检测字符串是否是整数
function Is_Int(a_str)
   if not isnumeric(a_str) or len(str) > 5 then
      Is_Int = false
      exit function
   elseif len(str) < 5 then
      Is_Int = true
      exit function
   end if   
   if cint(left(a_str , 4)) > 3276 then
      Is_Int = false
      exit function
   elseif cint(left(a_str , 4)) = 3276 and cint(right(a_str , 1)) > 7 then
      Is_Int = false
      exit function
   else
      Is_Int = true
      exit function
   end if   
end function

'检测是否是长整数
function Is_Lng(a_str)
   if not isnumeric(a_str) or len(str) > 10 then
      Is_Lng = false
      exit function
   elseif len(str) < 10 then
      Is_Lng = true
      exit function
   end if   
   if clng(left(a_str , 9)) > 214748367 then
      Is_Lng = false
      exit function
   elseif clng(left(a_str , 9)) = 214748367 and clng(right(a_str , 1)) > 7 then
      Is_Lng = false
      exit function
   else
      Is_Lng = true
      exit function
   end if   
end function

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