How to derive a variable name from a variable?
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How to derive a variable name from a variable?
A = [5 6 7 8];
B = ‘A’;
A(1) % this works and return the first element of A which is 5
B(1) % this doesn’t work like the code above
4 Comments
Stephen23
on 7 Feb 2017
What exactly are you trying to do? It doesn't sound like a good plan - dynamic variable names are a very bad idea.
A = [5 6 7 8];
B = A;
A(1);
B(1);
would give you what you want from the perspective of the information you have given, that you simply want B(1) to return the same as A(1).
Rightia Rollmann
on 7 Feb 2017
Adam
on 8 Feb 2017
If B is a field of A why are you trying to create a variable B that represents the whole of A.
Just A.( 'B' ) would give what you want. Fields are not really ordered in a struct, at least not for general usage.
Accepted Answer
Although often loved by beginners, dynamically accessing variable names is not a robust, fast, or good way to write code. It makes code hard to read, slow, difficult to debug, and has other disadvantages too:
If you really need to access the names dynamically, then consider using a structure: it is fast and easy to access structure field names dynamically:
S.A = [5,6,7,8];
x = 'A';
S.(x)
More Answers (2)
Star Strider
on 7 Feb 2017
MATLAB does not recognise char(0145) and char(0146) as quotation marks in code.
A = [5 6 7 8];
B = 'A' % Sets ‘B’ TO Be Character ‘A’
B = A
B(1)
produces:
B =
A
B =
5 6 7 8
ans =
5
A.B(:, 1:2)
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