why adding string to NSMutableArray not work?

Question

why adding string to nsmuarray not work? firstly, i add the a NSDictionary by keypath to the NSMutableArray, its work. after that i want to add one more string to that but its not work.

NSMutableArray *_joinornot;

_joinornot = [[NSMutableArray alloc] init];

NSDictionary *tempobject = [[NSDictionary alloc] init];

_joinornot = [tempobject valueForKeyPath:@"groupid"];

until now everything work.

[_joinornot addObject:@"111"];<----unrecongnized selector sent to instance

Where did you actually allocate an NSMutableArray and add it to the dictionary? — Paulw11
– Paulw11, Commented Jun 8, 2016 at 8:20

Fonix · Accepted Answer · 2016-06-08 08:24:59Z

2

if _joinornot = [tempobject valueForKeyPath:@"groupid"]; returns nil, then your array will be nil, and then you cant call addObject. so maybe add a nil check

answered Jun 8, 2016 at 8:24

Fonix

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1 Comment

Waitak Jong Over a year ago

i have check that its not nil before addobject

Vlad · Accepted Answer · 2016-06-08 08:37:04Z

0

Looks like "_joinornot" it's not an NSMutableArray or NSMutable data type, try to see what kind of object it is:

NSLog(@"%@", [_joinornot class]);

If it is not a subclass of Mutable type you can't add objects to him.

answered Jun 8, 2016 at 8:37

Vlad

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1 Comment

Vlad Over a year ago

If you want to add the string maybe this help: _joinornot = [[NSMutableArray alloc] initWithArray: _joinornot]; just before add the string

Ronak Chaniyara · Accepted Answer · 2016-06-08 08:44:37Z

0

Try below code:

Before adding object just check for nil.

NSMutableArray *_joinornot;

    _joinornot = [[NSMutableArray alloc] init];

    NSDictionary *tempobject = [[NSDictionary alloc] init];

    _joinornot = [tempobject valueForKeyPath:@"groupid"];

    if (_joinornot==nil) {

        _joinornot = [[NSMutableArray alloc] init];
        [_joinornot addObject:@"111"];
    }
    else{

        [_joinornot addObject:@"111"];
    }

Edit:

May be it's converted to NSArray so it will be no more mutable, try with

_joinornot = [[tempobject valueForKeyPath:@"groupid"] mutableCopy];

edited Jun 8, 2016 at 8:44

answered Jun 8, 2016 at 8:34

Ronak Chaniyara

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