蝸牛總是想落跑

數學函數 (Arithmetic Routines)

Unit: System
======================================================================
Abs 傳回參數的絕對值。 function Abs(X);
ArcTan 傳回正切函數的反函數值。 function ArcTan(X: Real): Real;
Cos 傳回餘弦函數值 function Cos(X: Real): Real;
(X 以弧度為單位)。
Exp 傳回自然指數值。 function Cos(X: Real): Real;
Frac 傳回參數的小數部份。 function Frac(X: Real): Real;
Int 傳回參數的整數部份。 function Int(X: Real): Real;
Ln 傳回自然對數值。 function Ln(X: Real): Real;
Pi 傳回圓周率π的值。 function Pi: Real;
Sin 傳回正弦函數值。 function Sin(X: Real): Real;
Sqr 傳回參數的平方。 function Sqr(X: Real): (Real);
Sqrt 傳回參數的平方根。 function Sqrt(X: Real): Real;

數字類的資料型態

Type Storage size Range

Byte 1 0 to 255
ShortInt 1 -127 to 127
Word 2 0 to 65,535
SmallInt 2 -32,768 to 32,767
LongWord 4 0 to 4,294,967,295
Cardinal 4* 0 to 4,294,967,295
LongInt 4 -2,147,483,648 to 2,147,483,647
Integer 4* -2,147,483,648 to 2,147,483,647
Int64 8 -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

Single 4 7 significant digits, exponent -38 to +38
Currency 8 50+ significant digits, fixed 4 decimal places
Double 8 15 significant digits, exponent -308 to +308
Extended 10 19 significant digits, exponent -4932 to +4932

* Note : the Integer and Cardinal types are both 4 bytes in size at present (Delphi release 7), but are not guaranteed to be this size in the future. All other type sizes are guaranteed.