A variable is a name used in a program to stand for a value. Nearly all programming languages have variables of some sort. In the text of a Lisp program, variables are written using the syntax for symbols.
In Lisp, unlike most programming languages, programs are represented primarily as Lisp objects and only secondarily as text. The Lisp objects used for variables are symbols: the symbol name is the variable name, and the variable's value is stored in the value cell of the symbol. The use of a symbol as a variable is independent of its use as a function name. See Symbol Components.
The textual form of a Lisp program is given by the read syntax of the Lisp objects that constitute the program. Hence, a variable in a textual Lisp program is written using the read syntax for the symbol representing the variable.blog comments powered by Disqus