Fundamental Concepts of Basic Language

1. Character Set:

The BASIC character set comprises all the ALPHABETS (A-Z), NUMERIC characters (digits 0-9) and some SPECIAL characters: !@#$%&*()_+-={}[];”,/<>?

2. Constants:

Constants are data elements supplied to BASIC. It could be in the form of Strings or Numeric constants.

A string constant is a sequence of characters enclosed in quotation marks, For example, “All that glitters is not gold”

A numeric constant is a number that can be used in calculations such as integer (whole number – 144), fixed point constant (any positive or negative real number with decimal points – 8.5, -2.0), floating point numeric constant (any positive or negative number represented in exponential form, for example, 75E+2 same as 7500, 75E-2 same as .75)

3. Variables:

A variable is a name that represents a number or string. It is a kind of storage location in your program. A variable for storing a numeric value is called a numeric variable, while that for storing a string value is called a string variable.

A numeric variable name must consist of a letter followed by an integer, for example, X2, C6, B, Q1, Y3. A string variable name consists of a letter followed by a dollar sign, for example, B$, X$, K$, C$. Most versions of BASIC also allow a string variable to be written as a letter followed by an integer, followed by a dollar sign, for example, B2$, X9$, C6$, K5$.