Fundamentals Overview IDE (Editor) Syntax Variables Data Types Declarations Scope Operators

Standard Functions Arithmetic Trigonometry Strings Arrays Date/Time Flow Control Procedures Printing Files Folders

Additional Capabilities Keyboard Sound Graphics Concepts Screen (text) Screen (drawing) Gaming (sprites) Event Trapping Errors System Calls

Arithmetic Functions Summary
As languages go, QBasic provides relatively few arithmetic functions. Example usage of each function is provided below, but as you can see the functions are very simple to use. The arithmetic functions can be categorized roughly into four areas:

Assignment	let, swap, clear
Program Data	data, read, restore
Logarithms	exp, log, sqr
Conversions	hex$, oct$
Conversions	abs, sgn, fix, mod, int
Random	rnd, randomize

Arithmetic Function Reference
Here's a quick reference of the available arithmetic functions, in alphabetical order. The functions are very simple to use.

Unless otherwise noted, these functions operate on $_ by default.

• abs - absolute value

      result = abs (-5)        # result is 5
       

• clear - closes all files, clears all common variables, reset values of all strings/numbers.

      clear                     # no arguments required
      

• data - specifies data for subsequent read statements

      data value1, value2, value3 ..     # comma separated value
      data 1, 4, 5, 7                    # numbers
      data "ab", "rs"                    # strings
      

  data statements may be entered only at the module level.

• exp - raises e to a value

      $result = exp (expression)   # raises e to the expression value
      

• fix - truncates a floating point value

      result = fix (2.63)      # returns 2
      

• hex$ - returns hexadecimal string representation of a number

      result$ = hex (79)        # returns "4F"
      

  Note: expression values are rounded to integers before converting

• int - returns largest integer less than or equal to expression

      result = int (79.8)      # returns 79
      

• let - assign value to a variable

      let result = 5
      

• log - natural (base e) logarithm

      result = log 1          # returns base e log of 1 - 2.718182
      

• mod - returns remainder of a division

      result = (expr1)MOD(expr2) # returns remainder of expr1/expr2
      result =  5.8 MOD 2.8      # returns 0 0 6/3=2 with no remainder
      

  Note: expression values are rounded to integers before dividing

• oct$ - returns octal string representation of a number

      result$ = oct$ (49)            # returns the string "61"
      result$ = oct$ (47.8)          # returns the string "61"
      

  Note: expression values are rounded to integers before converting

• randomize - initializes random number generator

      randomize (seed$)         # provides seed value
      randomize TIMER           # seed is seconds since midnight
      

• read - reads values from data statements

      data "one", "two", "three"    # data statement stores values
      read a$, b$, c$               # reads values from data statements
      

• restore - allows rereading of values

      data "one", "two", "three"    # data statement stores values
      read a$, b$, c$               # reads values from data statements
      restore line                  # next read start with data on line 
      read d$, e$, f$               # rereads values from data statement
      

• rnd - return random number between 0 and 1

      result = rnd        # new random number (no value)
      result = rnd (-5)   # same number (any value < 0)
      result = rnd (2)    # new random number (any value > 0)
      result = rnd (0)    # last random number (value = 0)
      

• sgn - returns sign of expression, or 0 if expression = 0

      result = sgn (-5)       # returns -1
      result = sgn (75)       # returns +1
      result = sgn (0)        # returns  0
      

• sqr - returns square root of a numeric-expression

      result = sqr (25)       # returns 5
      result = sqr (42)       # returns 6.480741
      

• swap - exchange values of two variables

      a$ = "a" : b$ = "b"   # set test values
      swap a$, b$           # a$ = "b" and b$ = "a" (values swapped)