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objective-cclassintrospectionobjective-c-runtime

How do I list all fields of an object in Objective-C?


If I have a class, how can I list all its instance variable names?

eg:

@interface MyClass : NSObject {
    int myInt;
    NSString* myString;
    NSMutableArray* myArray;
}

I would like to get "myInt", "myString", and "myArray". Is there some way to perhaps get an array of names that I can iterate over?

I've tried searching the Objective-C documentation but couldn't find anything (and I'm not sure what this is called either).


Solution

  • As mentioned, you can use the Objective-C runtime API to retrieve the instance variable names:

    unsigned int varCount;
    
    Ivar *vars = class_copyIvarList([MyClass class], &varCount);
    
    for (int i = 0; i < varCount; i++) {
        Ivar var = vars[i];
    
        const char* name = ivar_getName(var);
        const char* typeEncoding = ivar_getTypeEncoding(var);
    
        // do what you wish with the name and type here
    }
    
    free(vars);