Similar method in ObjectiveC for 'java.lang.Class.getDeclaredField()'

Question

I am reading a text file. I want to check whether there is a variable declared in the class with name same as the text that I read from the file.

Method for this in java is 'java.lang.Class.getDeclaredField()'. See http://www.tutorialspoint.com/java/lang/class_getdeclaredfield.htm for details.

I was unable to find similar method in ObjectiveC. Is there any? If no, how I can implement the same. Please give me few tips for that if you get any idea.

http://stackoverflow.com/questions/2299841/objective-c-introspection-reflection. Look at the first answer — giorashc, Apr 09 '13 at 06:14
@afsal: are you sure you need for ivar and there will be no property for those like @property/@synthesize? — Anoop Vaidya, Apr 09 '13 at 06:24
@AnoopVaidya Yes. I am sure. For example long Id; NSString* FirstName; — Afsal Meerankutty, Apr 09 '13 at 11:18
@AfsalMeerakutty: see my answers having for both. ivars and property — Anoop Vaidya, Apr 09 '13 at 11:58

Anoop Vaidya · Accepted Answer · 2013-04-09T06:38:27.820

1

You can check like this: /for properties/

YourClass *arrObj=[YourClass new];//your target class where you wnat to check
NSString *propertyName=@"samllArray";//this is what you will check in class YourClass
if([arrObj respondsToSelector:NSSelectorFromString(propertyName)]){
    NSLog(@"yes, exists");
}
else{
    NSLog(@"no, it does not exists");
}

EDIT:/for ivars/

- (NSMutableArray *)getAllPropertyOfClass:(Class)aClass {
    NSMutableArray *mArray=[NSMutableArray new];
    unsigned int outCount;
    Ivar *ivars = class_copyIvarList([aClass class], &outCount); //class_copyPropertyList([aClass class], &outCount);

    for(unsigned int i = 0; i < outCount; i++) {
        Ivar ivar = ivars[i];
        const char *propName = ivar_getName(ivar);
        if(propName) {
            NSString *propertyName = [NSString stringWithUTF8String:propName];
            mArray[mArray.count]=propertyName;
        }
    }
    free(ivars);
    return mArray;
}

edited Apr 09 '13 at 06:38

answered Apr 09 '13 at 06:16

Anoop Vaidya

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Close, but again, this is a poor replacement for actual introspection/reflection, and it doesn't account for iVars. Prefer the runtime methods outlined in the dupe over this. – CodaFi Apr 09 '13 at 06:18
I thought obj-runtime will be costlier – Anoop Vaidya Apr 09 '13 at 06:19
Your method checks if the class implements the `samllArray` method, not it if has an instance variable called `samllArray`. – Martin R Apr 09 '13 at 06:20
What does the speed of the runtime have to do with finding a comprehensive answer to this question? – CodaFi Apr 09 '13 at 06:21
Once I answered "Obj-C runtime" for similar question, then I was severely downvoted. I had a long discussion with DaveDLong. He used some great phrases. Now i am clueless, which way should I go. :( – Anoop Vaidya Apr 09 '13 at 06:23
1

I'd love a link to that question to get the context of the discussion you had. – CodaFi Apr 09 '13 at 06:25
I deleted my answer, after getting downvotes. – Anoop Vaidya Apr 09 '13 at 06:28
But what about the question? Does it still exist? – CodaFi Apr 09 '13 at 06:35

score -1 · Answer 2 · answered Apr 09 '13 at 06:15

-1

There are respondsToSelector and conformsToProtocol methods maybe they could help

answered Apr 09 '13 at 06:15

Alexander Kulyakhtin

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Those have nothing to do with dynamic introspection/reflection. A field in Java is analogous to an iVar, not a protocol. – CodaFi Apr 09 '13 at 06:17

Similar method in ObjectiveC for 'java.lang.Class.getDeclaredField()'

2 Answers2