How to monitor a variables that is outside of a function

Question

fa wu 2023-7-28

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2001897-how-to-monitor-a-variables-that-is-outside-of-a-function

评论： Walter Roberson 2023-7-29

This code . I type "aValue =SimpleHandle(10);" and then type "aValue. assignVar(20) ; %"

The programe will run in classdef SimpleHandle's methods "function assignVar(obj,var)" ,there is a Breakpoints. So programe will stop in obj.var = var;

At the same time ,I want to observe "aValue.var" ,but it isn't in workspace! because programe in "function assignVar(obj,var)",that make sense. But I type "aValue.var" in command line. Matlab notice "The function or variable 'aValue.var' is not recognized"

So is there any way can observe a variables that is outside of a function when programe run in the function? I think it is very useful as debugging.

"classdef SimpleHandle < handle 
    properties
        var
    end
    methods
        function obj = SimpleHandle(var)
            obj.var = var;
        end
        function assignVar(obj,var)
            obj.var = var;
        end
       
    end
end

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Stephen23 2023-7-28

"So is there any way can observe a variables that is outside of a function when programe run in the function?"

You could display them.

"I think it is very useful as debugging."

That is exactly what the debugging tools are for:

https://www.mathworks.com/help/matlab/debugging-code.html

Those tools include e.g. DBUP and DBDOWN ,which let you step up and down the workspaces.

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Answer 1

Steven Lord 2023-7-28

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2001897-how-to-monitor-a-variables-that-is-outside-of-a-function#answer_1280222

Functions operate in their own workspaces. The variable named aValue in the workspace of the caller of assignVar is not in the workspace of the assignVar call.

The debugging tools do allow you to switch workspaces to look at variables in other functions in the call stack. See the "View Variable Value Outside Current Workspace" section on this documentation page for instructions on how to do so.