ໃນ delphi ມີຫລາຍປະເພດ Number ຂື້ນຢູ່ກັບທ່ານເລືອກໃຊ້ໃນຊອບແວຂອງທ່ານ ດັ່ງລຸ່ມນີ້
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.
ການກຳໜົດໃຫ້ ຕົວປ່ຽນ Number
const YOUNG_AGE = 23; // Small integer constant MANY = 300; // Bigger integer constant RICH = 100000.00; // Decimal number : note no thousand commas var Age : Byte; // Smallest positive integer type Books : SmallInt; // Bigger signed integer Salary : Currency; // Decimal used to hold financial amounts Expenses : Currency; TakeHome : Currency; begin Age := YOUNG_AGE; // Assign from a predefined constant Books := MANY + 45; // Assign from a mix of constants (expression) Salary := RICH; // Assign from a predefined constant Expenses := 12345.67; // Assign from a literal constant TakeHome := Salary; // Assign from another variable TakeHome := TakeHome - Expenses; // Assign from an expression end;
ຜົນໄດ້ແມ່ນ
Age is set to 23 Books is set to 345 Salary is set to 100000.00 Expenses is set to 12345.67 TakeHome is set to 87654.33
Numerical operators
ສຳລັບການປະມວນ ໃຊ້ສັນຍາລັກຄື
+ : Add one number to another - : Subtract one number from another * : Multiply two numbers / : Divide one decimal number by another div : Divide one integer number by another mod : Remainder from dividing one integer by another
var myInt : Integer; // Define integer and decimal variables myDec : Single; begin myInt := 20; // myInt is now 20 myInt := myInt + 10; // myInt is now 30 myInt := myInt - 5; // myInt is now 25 myInt := myInt * 4; // myInt is now 100 myInt := 14 div 3; // myInt is now 4 (14 / 3 = 4 remainder 2) myInt := 14 mod 3; // myInt is now 2 (14 / 3 = 4 remainder 2) myInt := 12 * 3 - 4; // myInt is now 32 (* comes before -) myInt := 12 * (3 - 4); // myInt is now -12 (brackets come before *) myDec := 2.222 / 2.0; // myDec is now 1.111 end;
ຟັງຊັນ Numeric ແລະ procedures
ມີດັ່ງນີ້
Abs Returns the absolute value of a signed number Max Gives the maximum of two integer values Min Gives the minimum of two integer values Mean Gives the average of a set of numbers Sqr Gives the square of a number Sqrt Gives the square root of a number Exp Gives the exponent of a number Shl Shifts the bits in a number left Shr Shifts the bits in a number right Tan Gives the Tangent of a number Cos Gives the Cosine of a number Sin Gives the Sine of a number
ການປ່ຽນ ຈາກ numbers ເປັນ strings
Str Converts a number to a string in a simple manner CurrToStr Converts a Currency variable to a string Format Number to string conversion with formatting IntToStr Converts an integer to a string IntToHex Converts a number into a hexadecimal string
ການປ່ຽນຈາກ strings ເປັນ numbers
StrToInt Converts an integer string into an integer StrToIntDef Fault tolerant version of StrToInt StrToFloat Converts a decimal string to a number
[tag]Delphi, Number, type[/tag]
