Wolfram: Symbol
What is a Symbol
A symbol in WolframLang is similar to identifiers (e.g. variable names and function names) in other programing languages. But can be held unevaluated, just as a inert name by itself, like a string. It need not have a value. (it is like lisp's symbol. 〔see Elisp: Symbol〕)
Any sequence of letters you type into wolfram lang become symbols.
For example:
xx = {3, 4, b + 1}
(* {3, 4, 1 + b} *)
(* xx and b are symbols. b has no value. *)
(* set a value for b *)
b = 99
(* 99 *)
xx
(* {3, 4, 100} *)
(* b now has value. *)
WolframLang code is essentially a sequence of symbols and operators, such as
, [] () + - * / # &
etc.
〔see Wolfram: Syntax, Operators Cheatsheet〕
Some of the symbols, builtin or user-defined, has value. When a symbol has a value, the value automatically replaces the symbol. (or the function's return value replaces it.) This constitutes the heart of WolframLang computational model, a term-rewriting system.
Create Symbol Programatically (Convert String to Symbol)
Symbol[nameStr]-
Create a symbol and return it, if not already exist.
Convert Symbol to String
SymbolName[symbol]-
return the symbol name, as string.
List Existing Symbols
Names[globPatternStr]-
List existing symbols. The pattern string can include a asterisk to stand for any char or none.
(* list all symbols whose name contains String *) Names["*String*"]