Valid identifiers in MATLAB:
- Must start with a letter, followed by a combination of letters, digits and underscores
- Cannot be a reserved word
- Their length must be lower than or equal to the value returned by
% Maximum identifier length maxLength = namelengthmax;
maxLength = 63
MATLAB is a case-sensitive programming language, so lowercase and uppercase letters are different entities and generate different identifiers.
% These are different variables myVar = 1; MyVar = 2;
myVar = 1
MyVar = 2
Variable: Abstraction of a computer memory cell or collection of cells, characterized by its name, address, value, type, lifetime, and scope .
Avoid creating variables with the same name as a function, because variable names take precedence over function names, which can generate unexpected results in certain situations.
A = 1; size = [7, 8, 9]; % Bug: 'size' is used as a function, but in this context it is a variable rowsCount = size(A,1);
rowsCount = 7
I recommend the following books to learn more on how identifiers are treated in MATLAB and other programming languages:
This book was the winner of a Textbook Excellence Award. The first chapter explains MATLAB identifiers, reserved words, and other introductory topics.
Concepts of Programming Languages (11th Edition)
This book covers the fundamental topics of programming languages. Chapter 4 describes what identifiers, reserved words, variables, bindings, and scopes are in programming languages.
I also recommend the following pages in the MATLAB help documentation, and the other tutorials in this series.
doc namelengthmax; doc isvarname;
- Getting Help in MATLAB
- Valid Identifiers in MATLAB
- Reserved Words in MATLAB
- Comments in MATLAB
- Multiline Statements in MATLAB
- How to Execute a Command Automatically When MATLAB Starts
- How to Execute a Command Automatically When MATLAB Quits
- How to Save the Workspace Variables to a .MAT File in MATLAB
- How to Load the Variables in a .MAT File into the Workspace in MATLAB
- How to Delete a Variable in MATLAB
I hope you have understood how identifiers are treated in MATLAB. The source code developed in this tutorial is available at this page.