How do I search for variable names in the editor?

Question

In functions, the MATLAB editor displays a warning when a defined variable is not subsequently used before the function ends or before the variable is overwritten. This obviously tells me that the editor has a way of searching for occurrences of given variables in the code.

Can I do this manually? The Find function is obviously limited here, since it only searches the body of text in the editor window (including comments) for matches of the search string. This makes it very inconvenient when searching for variables with short names (such as the by me commonly used "a").

Answer 1

You can limit the search to match case and whole word, which will give you only this variable, either in comment or not.

BTW, you shouldn't use variable names like a,b,c. It makes the code harder to read and to maintain. Even if you have dummy variables like in loops and temporary ones, use for example indexFiles, or tempValue

Answer 2

I cannot tell you about previous versions of the built-in editor, but at least from 2011b, the righthand side margin of the editor creates color tags for:

• Warnings, tagged in orange
• Errors, tagged in red color
• Variable/function occurrence: tagged in dark gray, for selected text.

The third of them is what you are looking for. You just have to double click on a variable name or a function name to select it and your Matlab editor will automatically highlight the rest of the occurrences of the very same identifier, tagging them on the righthand side ribbon with the grey mark I mentioned above.

Answer 3

You can also use some regular expression to match the variable names in your code.

If you'll assume that any variable name is separated from the rest of the code by any of linefeed tab space ! " # $ % & ' ( ) * + , - . / : ; < = > ? [ \ ] ^ `` { | } ~, then you can create a small function that takes the function name as input and outputs the lines in which the variable name is mentioned. However, this approach doesn't separate function names and variable names, but you should have some standard for separating them anyway. I use this approach to change variable names of my MATLAB code (but my code for that is written in awk, not in MATLAB).

And I wonder what you'll do when you have a complex program with thousands or tens of thousands of lines of code and your variables are named a, b, c and so on...