Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
454 views
in Technique[技术] by (71.8m points)

iphone - Is there something like Matlab's eval statement in Objective-C 2.0?

I am new to Objective-C and I am looking for an eval statement like I have used in Matlab.

If you are not familiar with this, you can build a character string and then eval that string, which treats it like it is a line of code.

Here is a example where you would want to change the background color of one of a series of 4 buttons based on a variable foo which = 3 and you buttons would be named button1, button2 etc.

NSString* buttonEval = [[NSString alloc] initWithFormat:@"[button%d setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];", foo]

Is there a statement the will evaluate this string as if it was a line of code?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

This is not a common feature in compiled languages, which Objective C qualifies as. This is because the mechanisms and "intelligence" needed to convert source code into something the CPU can run is contained in the compiler, which is no longer around when the code runs.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...