delphi syntax:
function vartype(const v: variant): tvartype;
vartype contents of variant
varempty the variant is unassigned.
varnull the variant is null.
varsmallint 16-bit signed integer (type smallint in delphi, short in c++ ).
varinteger 32-bit signed integer (type integer in delphi, int in c++).
varsingle single-precision floating-point value (type single in delphi)
vardouble double-precision floating-point value (type double).
varcurrency currency floating-point value (type currency).
vardate date and time value (type tdatetime).
varolestr reference to a dynamically allocated unicode string.
vardispatch reference to an automation object (an idispatch inte***ce pointer).
varerror operating system error code.
varboolean 16-bit boolean (type wordbool).
varvariant a variant.
varunknown reference to an unknown object (an iinte***ce or iunknown inte***ce pointer).
varshortint 8-bit signed integer (type shortint in delphi or signed char in c++)
varbyte a byte
varword unsigned 16-bit value (word)
varlongword unsigned 32-bit value (type longword in delphi or unsigned
varint64 64-bit signed integer (int64 in delphi or __int64 in c++)
varstrarg com-compatible string.
varstring reference to a dynamically allocated string (not com compatible).
varany a corba any value.
unit untvartype;
inte***ce
uses
windows, messages, sysutils, variants, classes, graphics, controls, forms,
dialogs, stdctrls;
type
tform1 = class(tform)
button1: tbutton;
label1: tlabel;
procedure button1click(sender: tobject);
private
public
end;
varform1: tform1;
implementation
獲取變數的資料型別
function getvartype(value: variant):string;
begin
case vartype(value) of
varempty : result :='unassigned';
varnull : result := 'null';
varsmallint : result := 'smallint';
varinteger : result := 'integer';
varsingle : result := 'single';
vardouble : result := 'double';
varcurrency : result := 'currency';
vardate : result := 'tdatetime';
varolestr : result := 'olestr';
vardispatch : result := 'dispatch';
varerror : result := 'error';
varboolean : result := 'boolean';
varvariant : result := 'variant';
varunknown : result := 'unknown';
varshortint : result := 'shortint';
varbyte : result := 'byte';
varword : result := 'word';
varlongword : result := 'longword';
varint64 : result := 'integer';
varstrarg : result := 'strarg';
varstring : result := 'string';
varany : result := 'any';
end;
end;
測試procedure tform1.button1click(sender: tobject);
vari: integer;
w: word;
b: boolean;
e: tdatetime;
begin
showmessage(getvartype(i));
showmessage(getvartype(w));
showmessage(getvartype(b));
showmessage(getvartype(e));
end;
end.
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希望在這一點上，你會說，嘿，等一下，我不應該用浮點值做 的比較！然後你可以修改它以更適當的前進。從長遠來看，這會節省你很多時間。傳統的匈牙利命名法真正的缺點是對各種型別的化合物的字首的數量可以變得混亂。維基百科提供了乙個恰當的例子 a crszkvc30lastnamecol 乙個恆定的參考函式的引...