I'm struggling to get my array to print the correct data.
I've got it linked to a button, so it gets the textfield data and adds it to a Person class which has a subclass called PhoneBookEntry which contains firstName, and then adds it to an NSMutableArray called entries. here's the button code:
PhonebookEntry *person = [[PhonebookEntry alloc] init];
self.firstName.text = person.firstName;
[self.entries addObject:person];
NSLog(#"%#", self.entries);
Here's the start where I initialise everything:
#interface ViewController ()
#property (nonatomic, strong) PhonebookEntry *person;
#property (nonatomic, strong) NSMutableArray *entries;
#end
in my viewDidLoad, this is the code to create the NSArray.
self.entries = [NSMutableArray arrayWithCapacity:1];
I've tested and it works fine when adding normally and prints etc, just not with the array.
Thanks
The output
test,
test2,
"<PhonebookEntry: 0x8c69770>"
It is printing correctly.
Actually you want something more from your code or Objective-C.
For this you need to override description in PhonebookEntry class to break to the level where NSLog can print. NSLog can't print person object values.
-(NSString *)description{
return [NSString stringWithFormat:#"%# , %#", self.firstName, self.lastName];
}
This self.firstName.text = person.firstName; should be the other way around, so change it to this:
person.firstName = self.firstName.text;
Related
When I assign one array to another, I get an error, as shown in P1.
Then I checked the contents of _carIDArray and found an empty object in it. It was this object that caused the crash.P2
Why do empty objects appear in arrays? When using addobjcet: will not the array crash?
Here's some codes related to _carIDArray:
CarModel *car = [[CarModel alloc] initWithStatusAndMsgWithDic:object];
if (!_carIdArray) {
_carIdArray = [NSMutableArray array];
}
if (car.carIdStr && car.carIdStr.length>0){
[_carIdArray addObject:car.carIdStr];
}
*object is the data from the server.
#interface CarModel : NSObject
#property (nonatomic,copy) NSString *carIdStr;
#end
I am calling a web service which returns dictionary to render the graph. Dictionary structure is
{"1":0,"2":0,"8":0,"9":2,"10":3,"11":0,"12":0}
The problem is keys are dynamic values like 1,2,3 etc which indicates month. Is it possible to represent this in JsonModel?
See you cant create properties at run time as per response structure. But we can smartly use pre-defined things and achieve this. Do following steps:
Create one model class. So your MyCustomModel.h file will look like this
#import <Foundation/Foundation.h>
#interface MyCustomModel : NSObject
#property (nonatomic, retain) NSString * myCustomKey;
#property (nonatomic, retain) NSString * myCustomValue;
#end
This will be your MyCustomModel.m file
#import "MyCustomModel.h"
#implementation MyCustomModel
#synthesize myCustomKey, myCustomValue;
-(id)init {
self = [super init];
myCustomKey = #"";
myCustomValue = #"";
return self;
}
#end
Now lets suppose {"1":0,"2":0,"8":0,"9":2,"10":3,"11":0,"12":0} is NSDictionary and lets say its name is dictionaryResponse
Now do this stuffs:
NSArray *responseKeys = [[NSArray alloc]init];
responseKeys = [dictionaryResponse allKeys];
So your responseKeys will have all keys of response like ["1","2","8","9","10","11","12",]
Now you can iterate loop and create NSMutableArray of model objects as
NSMutableArray *arrayMonthList = [[NSMutableArray alloc]init];
for (int i = 0; i < responseKeys.count; i++) {
MyCustomModel *myModelObject = [[MyCustomModel alloc]init];
myModelObject.myCustomKey = [NSString stringWithFormat:#"%#",[responseKeys objectAtIndex:i]];
myModelObject.myCustomValue = [dictionaryResponse valueForKey:[NSString stringWithFormat:#"%#",[responseKeys objectAtIndex:i]]];
[arrayMonthList addObject:myModelObject];
}
Now arrayMonthList will consist of objects of type MyCustomModel
So you can use it and parse it. Even you can use it to show on UITableView. Following code is written to print values of model properties, you can customise at your expected level.
for (int i = 0; i < arrayMonthList.count; i++) {
MyCustomModel *myModelObject = [arrayMonthList objectAtIndex:i];
NSLog(#"Month is %# and its value is %#",myModelObject.myCustomKey,myModelObject.myCustomValue);
}
I declare the following in ViewController.h
#property (nonatomic, strong) NSMutableArray *locations;
and the following in ViewController.m
#implementation GHViewController
#synthesize locations;
...
for (FSFourSquareVenueObject *object in array) {
locations = [[NSMutableArray alloc] init];
[locations addObject:object.locationName];
NSLog(#"%#", locations);
}
This successfully logs all the string locations that have been placed in the locations NSMutableArray. How can I access this NSMutableArray in a different class?
I am trying to access it in my TableViewController class in order to display all the elements in the array. I have tried importing the ViewController.h file into my TableViewController.h file, yet I still cannot access the array from the ViewController class.
Remove the line
locations = [[NSMutableArray alloc] init];
from your for loop and place it somewhere like viewDidLoad or init. You're wiping out your array every time before adding a new object.
To access a single object across classes, you want to look into creating a singleton. There are many tutorials online.
Do as #Stonz2 suggests, but also modify your headers as follows:
In GHViewController.h:
#property (nonatomic, strong) NSArray *locations;
In GHViewController.m
#implementation GHViewController
#synthesize locations;
...
NSMutableArray *array = [[NSMutableArray alloc] init];
for (FSFourSquareVenueObject *object in array) {
[array addObject:object.locationName];
NSLog(#"%#", array);
}
self.locations = [array copy];
You can then access the array from another class using GHViewController -locations. You can edit the locations using the following snippet (or by creating a similar method in GHViewController):
NSMutableArray *array = [gh_viewController.locations mutableCopy];
[array addObject: newLocation];
gh_viewController.locations = [array copy];
Exposing a mutable array allows other class to modify the array without notifying GHViewController and vice versa. This can lead to unpredictable and hard to debug problems, such as if GHViewController removes some elements while TableViewController is iterating through all the objects. Using a non-mutable array prevents these sorts of bugs and ensures everyone has a consistent view of what's inside.
I'm new to iphone app development and I'm stuck on this problem I'm having with the app I'm trying to develop.
I have a datacontroller for populating a tableview. I created it using this tutorial:
About Creating Your Second iOS App
I'm trying to pass an array from one of my viewcontrollers that was created from a JSON response.
Here is some code from my viewcontroller.h that needs to pass the array:
#interface ViewController : UIViewController
#property (nonatomic, retain) DataController *Data;
#property (nonatomic, retain) NSMutableArray *array;
#end
viewcontroller.m:
#import "DataController.h"
[Data setMasterList: self.array];
DataController.h:
#interface DataController : NSObject
#property (nonatomic, strong) NSMutableArray *masterList;
- (void)setMasterList:(NSMutableArray *)newList;
#end
DataController.m
#import "LoginViewController.h"
- (void)setMasterList:(NSMutableArray *)newList {
if (_masterList != newList) {
_masterList = [newList mutableCopy];
NSLog("List: %#", newList);
}
}
The NSLog message never shows up in the console and the array is nil.
Any help is appreciated.
Thanks.
EDIT:
Here's the updated viewcontroller.m:
Data = [[DataController alloc] init];
[Data setMasterList: self.array];
The datacontroller.m:
- (void)setMasterList:(NSMutableArray *)newList {
if (_masterList != newList) {
_masterList = [newList mutableCopy];
NSLog("List: %#", self.masterList);
}
}
- (NSUInteger)countOfList {
NSLog("List: %#", self.masterList);
return [self.masterList count];
}
The first nslog inside setMasterList returns the correct array values, but the second nslog inside countOfList returns null. The list always returns null anywhere outside of setMasterList. Is it because I'm creating a new instance of the DataController? If so, how else could I pass the array to the datacontroller.
As in first comment Till have suggested, Data must be initialized before calling setMasterList. Such As:
Data = [[DataController alloc] init];
[Data setMasterList: self.array];
please help me to solve a simple problem.
I am a beginner in objective-c, and I am just switched to objective-c from java. I know java fair well, but not quite super deep into it.
I am building a iphone app. My app is quite simple.
The purpose of my iphone app is to take order with my iphone app in a restaurant.
Progress of My App:
My app only has couple viewPanels and buttons now :)
Here is my app sourcecode, firstview screenshot & secondview screenshot
Problem:
When i click on the Coffee button, my textField wont show up the coffee name & coffee price, which suppose to show up " coffee 1" .
and xcode will take me to the debugger from the iphone similator.(i think its crush at a line so the dubugger took me to the IBaction method and break at the line #synthesize name; It compiles with no error. please help trouble shoot why xcode take me to debugger when i press the coffee button.
SCREEN SHOWS UP RIGHT AFTER PRESS THE COFFEE BUTTON
here is the action code of the coffee button
- (IBAction)Coffee:(id)sender {
int price = 1;
NSString *name = #"coffee";
Storage *order = [[Storage alloc] init];
[order setName:name]; // i assume the program crush at here when it look into setName method.
[order setPrice:price];
[orders addOrders:order];
// Sanity check: // the program not even hit this line yet before crush;
NSLog(#"There are now %d orders in the array.", [orders.getOrders count]);
for (Storage *obj in orders.getOrders){
[check setText:[NSString stringWithFormat:#"%#",[obj description]]]; // check is the TextField instant varible. and the description method is from storage.m to print out the name and price.
}
}
The codes below are my storage classes that store all items that my customer orders.
it is a 2 dimensional array, and My Storages class is a wrapper class of Storage class.
the array format looks like this:
arrayindex1-> name, price
arrayindex2-> name, price
arrayindex3-> name, price
arrayindex4-> name, price
Storage.h
#import <Foundation/Foundation.h>
#interface Storage : NSObject
#property (nonatomic, strong) NSString *name;
#property (nonatomic, assign) NSInteger price;
#end
Storage.m
#import "Storage.h"
#implementation Storage
#synthesize name; // program crush and goes to here.
#synthesize price;
- (NSString *)description {
// example: "coffee 1"
return [NSString stringWithFormat:#"%# %d", self.name, self.price];
}
#end
Storages.h
#import <Foundation/Foundation.h>
#import "Storage.h"
#interface Storages : NSObject
#property (nonatomic,strong, readwrite) NSMutableArray *orders;
-(void) addOrders:(Storage *)anOrder;
-(NSMutableArray *) getOrders;
#end
Storages.m
#import "Storages.h"
#implementation Storages
#synthesize orders;
- (id)init {
self = [super init];
if (self) {
orders = [[NSMutableArray alloc] init];
}
return self;
}
-(void) addOrders:(Storage *)anOrder{
[orders addObject: anOrder];
}
-(NSMutableArray *) getOrders{
return orders;
}
#end
There are a couple of problems here.
1) Don't use a pointer for the price property. Generally, unless you're doing something unusual, your properties that are objects will be pointers and your properties that are primitives (NSInteger, BOOL, float, etc) will not be pointers.
2) You will want to make sure that the orders NSMutableArray is initialized with the Storages object, otherwise orders will remain nil and whenever you try to add objects to it, nothing will happen. To initialize the NSMutableArray, do this in your init method as shown below. You can also check that the object is actually getting into a valid mutable array this by putting a simple NSLog statement in the for (Storage *obj in orders.getOrders) { ... } loop and making sure you get at least one iteration through the loop. If orders.getOrders is nil, the work block of the for loop will never get run.
3) It sounds like you need to override (and may have already overridden) the -[NSObject description]method for your Storage object. My guess is you have a mismatch in this method with the -[NSString stringWithFormat:...] format string. For example, you might be using %d or %# in the format string for the NSInteger *. Something like that could definitely cause a crash (which is what I think you mean by "Xcode taking you to the debugger"). For NSIntegers you need to use %d or %i. And as myself and others have mentioned, you want NSInteger here and not NSInteger * and you should change your property declaration.
4) Based on what you have here, I don't think you need the order property in the Storages class at all.
5) Make sure you haven't overlooked the possibility of forgetting to hook up the IBOutlet in Interface Builder to the check textField. A good test for this, besides just confirming it's connected in Interface Builder, would be a reality check test like [check setText:#"This is a test."];
6) Keep in mind that once this works, your for loop is going to execute very quickly, and you'll immediately see only the description for the last object in the orders array. But that doesn't seem to be what your question is about.
I'd suggest you make the following changes:
Storage.h
#import <Foundation/Foundation.h>
#interface Storage : NSObject
#property (nonatomic, strong) NSString *name;
#property (nonatomic, assign) NSInteger price;
#end
Storage.m
#import "Storage.h"
#implementation Storage
#synthesize name;
#synthesize price;
- (NSString *)description {
// example: "coffee 1"
return [NSString stringWithFormat:#"%# %d", self.name, self.price];
}
#end
Your IBAction method
- (IBAction)Coffee:(id)sender {
int price = 1;
NSString *name = #"coffee";
Storage *order = [[Storage alloc] init];
[order setName:name];
[order setPrice:price];
[orders addOrders:order];
// Sanity check:
NSLog(#"There are now %d orders in the array.", [orders.getOrders count]);
for (Storage *obj in orders.getOrders){
[check setText:[NSString stringWithFormat:#"%#",[obj description]]]; // check is the TextField instant varible. and the description method is from storage.m to print out the name and price.
}
}
Storages.h
#import <Foundation/Foundation.h>
#import "Storage.h"
#interface Storages : NSObject
#property (nonatomic,strong, readwrite) NSMutableArray *orders;
-(void) addOrders:(Storage *)anOrder;
-(NSMutableArray *) getOrders;
#end
Storages.m
#import "Storages.h"
#implementation Storages
#synthesize orders;
- (id)init {
self = [super init];
if (self) {
orders = [[NSMutableArray alloc] init];
}
return self;
}
-(void) addOrders:(Storage *)anOrder{
[orders addObject: anOrder];
}
-(NSMutableArray *) getOrders{
return orders;
}
#end
What does description do in the following? (I cannot see any description object in Storage class):
[check setText:[NSString stringWithFormat:#"%#",[obj description]]];
I think if you want to print the name the do like:
[check setText:[NSString stringWithFormat:#"%#: %#",obj.name, obj.price]];
You have taken NSInteger pointer in Storages class which is not correct. NSInteger is basic data type and not a pointer. Remove that pointer and use NSInteger variable.
I hope this would resolve your problem.
You could use below code:
#interface Storage : NSObject
#property (nonatomic, retain)NSString *name;
#property (nonatomic, assign)NSInteger price;
You have two mistakes:
1- You declared price as an NSInteger and passed it as a reference. The correct is to pass it as an integer as it is and deal with it as an integer through the whole application.
2- You didn't initialize orders array in Storages class so it will be always nil and will not hold any added object.
You code may looks like:
In the button's IBAction pass the price directly
[order setPrice:price];
In the Storage class
- (NSString *)description {
return [NSString stringWithFormat: #"%# %d", name, price];
}
Add the following to the Storages class
-(id)init
{
if (self = [super init])
{
orders = [[NSMutableArray alloc] init];
}
return self;
}