Objective C 等价于 PHP 的“可变变量"； [英] Objective C Equivalent of PHP's "Variable Variables"

问题描述

In PHP and in JavaScript you can dynamically use a variable by using another variable as part of its name. I do not want to use an array as part of the solution. Can this be achieved in Objective C? I'd like to do something like this:

for (int i=1; i<6; i++) {
        if([appRecord.answer(i) length] != 0){
            self.textView.answer(i)ViewSingle.text = appRecord.answer(i);
        }
}

解决方案

Short answer: No.

Long answer: Kind of.

1. You can use an array, store your variables in there, and index into it.
2. Like #1, if your objects are actually UI elements and you don't want a whole bunch of IBOutlets, then use an IBOutletCollection instead.
3. You can use a dictionary, store your variables as values, and look them up by key.
4. You can declare all your variables as @property, and then use [self valueForKey:] to look them up by name.
5. You can build the name of the ivar as a string, and then use something like object_getInstanceVariable() to retrieve it's value directly (this is similar to #3, except you don't have to declare it as an @property). This is excessively complicated and is usually a much bigger hammer than you'll actually need.
6. If you're dealing with views, you can assign each view a unique tag and then retrieve it via [superview viewWithTag:aTag]. I do not recommend using this approach.

EDIT: Note that this only works with instance variables. This does not work with global/static variables.

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