How to define a string variable in IF statement
显示 更早的评论
I'm stuck with matlab on almost every simple step I used to work with pretty fast in PHP. How this piece of code inside my function makes me crazy:
matchStr = regexp(filename,'^([0-9\-])+-StockAndOptionQuoteFor([A-z]+)\.', 'tokens');
CurDate = matchStr{1,1}{1,1};
if(~Ticker)
Ticker = matchStr{1,1}{1,2};
end
Matlab keeps telling "Undefined function or variable 'Ticker'." or The variable 'Ticker' might be used before it is defined! But it's a standard practice in PHP. How do I know which type of variable it would be, a string or double?
Ticker='' didn't help
采纳的回答
Andrei Makarskiy
2015-10-15
编辑：Andrei Makarskiy
2015-10-15
1 个评论
Star Strider
2015-10-15
Using global variables is not considered good programming practice, and can cause problems. Add the variable to the function argument list instead.
更多回答（1 个）
the cyclist
2015-10-15
Spoiler alert: Different languages have different syntax. :-)
Are you trying to check if a variable named "Ticker" exists, and then create it if it does not? Then use the exist function
if ~exist('Ticker','var')
Ticker = matchStr{1,1}{1,2};
end
In MATLAB, "~" means logical negation.
2 个评论
Andrei Makarskiy
2015-10-15
the cyclist
2015-10-15
This is an example of Star Strider's comment about defining global variables being a generally bad practice. Debugging problems can be a challenge, because code that is "far away" and difficult to find can affect something local.
类别
在 帮助中心 和 File Exchange 中查找有关 Workspace Variables and MAT Files 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
