This chapter lists the global statements and procedures that form the core of the twinBASIC language.

Warning

Work in Progress Below

Categorical List

Compiler Control

• Option - configure a compiler option
• #If … Then … Else - enable or disable compilation of enclosed code

Declarations and Definitions

• Class, Module - define a class or module
• Sub - define a procedure
• Function - define a function
• Property - define a property
• Enum - define an enumeration type with associated constants
• Type - declare a user-defined data type (UDT)/a structure
• Declare - declare an external/library procedure or function
• Event - declare an event
• Implements - specifies that a class implements a given interface
• End - terminate execution, finish a Function, Sub, Property, or Enum definition, finish a Type declaration; finish a Class or Module, finish an If, Select, or With block

Flow Control

Statements:

• Call - invokes a procedure or function
• Do … Loop, For … Next, While … Wend - loops
• If … Then … Else - execute code conditionally
• Continue - skip to the next iteration of the loop
• Exit - exit a loop, procedure, function or property
• Select Case - execute a code block selected by an expression
• With - bring a variable or expression into scope
• Goto, GoSub … Return - transfer execution to another location
• Resume - resumes execution after an error has been caught
• On Error - specifies what to do when an error occurs
• On … GoTo, On … GoSub - transfer execution to a location selected by an expression
• Stop - interrupt execution

See also:

• End - terminate execution.

Variable Declaration

Statements:

• Dim - declare a typed scalar or array variable
• Const - declare a constant
• Public - declare a public variable in a class or module
• Private - declare a private variable in a class or module
• Static - declare a a variable of static duration

See also:

• Erase - clear/fill an array
• ReDim - change the size of an array

Variable Assignment and Modification

Statements:

• Let - sets the value of a variable
• Set - changes the object referred by the variable
• Erase - fills a fixed-size array with default values, or invalidates a dynamic array
• LSet - assigns a user-defined type, or left-aligns a string
• RSet - right-aligns a string
• ReDim - change the size of a dynamically-sized array,

File I/O

Statements:

• Open, Close - open/close a file for I/O operations
• Get, Put - read/write data from an open random access file
• Line Input, Print - read/write a line from/to an open text file
• Input, Write - read/write data from an open sequential access file
• Seek - change the current access position in an open file
• Lock, Unlock - lock/unlock a range of records in an open file

Procedures:

• Reset - close all open disk files
• Width - set the limit for line lengths when printing
• ChDir, ChDrive - change the current working directory and disk drive
• MkDir, RmDir - create/remove a directory on disk
• Name - rename a file or directory on disk
• SetAttr - set attributes of a file on disk
• FileCopy - copy a file on disk
• Kill - delete a file from disk
• SavePicture - write a Picture or Image to a disk file

State Management

Procedures:

• Load, Unload - load/unload a form or control into memory
• GetSetting, SaveSetting - retrieve/store a string value from/to the system registry
• DeleteSetting - remove value from the system registry

Events and Interaction

Statements:

• RaiseEvent - raise an event that may be handled by event handlers

See also

• Event - declare an event

Procedures:

• AppActivate - change the focus to, or activate, a named window
• Beep - sound a system beep
• SendKeys - send keystrokes to the active window

Mathematics

Procedures:

• Atn, Cos, Sin, Tan - trigonometric functions
• Sqr - take a square root
• Exp - calculate an exponential with base $e$
• Log - calculate the natural (base $e$) logarithm of a number
• Sgn - return the sign of a number
• Abs - returns the absolute value of a number
• Round - round the number to a given number of decimal places
• Rnd - generate a random number in the range [0.0, 1.0)
• Randomize - seed the random number generator

String Handling

Statements that modify strings:

• Mid =, MidB = - assign to or replace characters or wide/narrow string sections

Procedures that check properties of strings:

• Len$, Len, LenB$, LenB - the length of a string
• Asc, AscB, AscW - returns the character code of the first letter in a string
• StrComp - compares two strings
• InStr$, InStrB, InStr - finds the position of a given substring in a string

Procedures that create strings:

• Chr$, Chr, ChrB$, ChrB, ChrW$, ChrW - returns the character having a given code
• Space$, Space - return a string of spaces
• String$, String - return a string of specified characters

Procedures that return modified strings:

• Left$, Left, LeftB$, LeftB - extract a left substring of a string
• Mid$, Mid, MidB$, MidB- extract a substring of a string
• Right$, Right, RightB$, RightB - extract a right substring of a string
• LTrim$, LTrim, RTrim$, RTrim - removes leading/trailing spaces from a string
• Trim$, Trim - removes leading and trailing spaces from a string
• StrReverse - reverses the order of characters of a string
• LCase$, LCase, RCase$, RCase - capitalizes or lowercases a string
• StrConv - converts the string to a specified format
• Join - concatenates a string array using a given delimiter
• Split - splits a string into a string array
• Replace - replaces substrings in a string
• Filter - filters a string array into a subset according to criteria
• InStrRev - filters a string array into a subset according to criteria
• Format$, Format - format a numeric expression in a specific way
• FormatNumber - formats an expression as a numeric string
• FormatPercent - formats an expression as a percent string

See also:

• FormatCurrency - format an expression as a currency string
• FormatDateTime - formats an expression as a date/time string

Date and Time

Procedures:

• Date, Time - set the current date and time
• FormatDateTime - formats an expression as a date/time string
• MonthName - returns the name of the specified month
• WeekdayName - returns the name of the specified day of the week

Financial

Procedures:

• DDB - depreciation of an asset via the Double-Declining Balance method
• FV - future value of an investment with constant deposits and interest
• Pmt - payment for a loan with constant payments and interest
• IPmt - interest payment for a loan with constant payments and interest
• PPmt - principal payment for a loan with constant payments and interest
• SYD - sum-of-years’ digits depreciation of an asset
• SLN - straight-line depreciation of an asset in one period
• PV - present value of investment
• IRR - internal rate of return for a series of cash flows
• MIRR - modified internal rate of return for a series of cash flow
• Rate - interest rate per period of an annuity
• NPV - net present value of an investment
• NPer - number of periods for an investment with constant deposits and interest
• FormatCurrency - format an expression as a currency string

Deprecated

Statements:

• DefBool, DefByte, DefInt, DefLng, DefCur, DefSng, DefDbl, DefDec, DefDate, DefStr, DefObj, DefVar - used to give implicit types to single-letter variables
• Error - raise an error