constant string definition
A constant, also known as a literal or a scalar value, is a symbol that represents a specific data value. The format of a constant depends on the data type of the value it represents. Character string constants. Character string constants are enclosed in single quotation marks and include alphanumeric characters (a-z, A-Z, and 0-9) and special characters, such as exclamation point (!), at sign (@), and number sign (#).