Turbo Basic

ConstantsTurbo Basic programs process two distinct classes of data: constants and variables(discussed after this section). A variable is allowed to change its value asa programruns. A constant's value is fixed at compile time and cannot change. during programexecution. Turbo Basic supports three types of constants: string constants, numericconstants, and in an extension to Interpretive BASIC, a special form of integerconstant, named constants.String ConstantsString constants are simply groups of characters surrounded by double quotes; forexample:"This is a string""3.14159""Tim Jones, Attorney at law"If a string constant is ,the last thing on a line, the closing quotes are optional:PRINT "This is sloppy but legal.Numeric ConstantsNumeric constants represent numeric values, and consist primarily of the digits 0through 9 and a decimal point. Negative constants need a leading minus sign (-);a plus sign (+) is optional for positive constants. The amount of precision yousupply determines the internal representation (integer, long integer, single precision,or double precision) Turbo Basic will use in processing that constant.If the value contains no decimal point and is in the range -32,768 to 32,767, thenTurbo Basic uses its integer type.If the value is an integer in the range - 2 31 to 2 31 - 1 inclusive (about - 2 billion to+ 2 billion), yet outside the range for integer constants, Turbo Basic uses its longinteger type. (Note: The long integer type is not available in Interpretive BASIC.)If the value contains a decimal point, and has up to six digits, Turbo Basic usesits single-precision floating-point type.68 Turbo Basic Owner's Handbook