Does evalin make a copy or use a reference to the base variable?
3 次查看(过去 30 天)
显示 更早的评论
Does evalin use additional memory when assigning the variable in the function or does it use a reference?
alpha = evalin('base','alpha');
0 个评论
采纳的回答
Walter Roberson
2019-11-12
At one level of abstraction, calling a function normally is equivalent to pulling out the function header and setting up the parameter list, and then using eval on the code.
eval() and evalin() are not somehow emulating code: they use the normal internal expression tokenizer, getting back a parse tree, which is submitted to the execution engine. This is not just "like" how matlab executes functions and scripts: it is how matlab executes functions and scripts.
Thus, evalin() processes the same way the line of code would be processed intthat environment (except possibly details of caching), so it would give whatever result that code would. Which is to say that copy-on-write is used, which provides references to variables.
0 个评论
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Whos 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!