Given a basic key/value array, I'm wanting to store two sorted arrays based on the original array: one array will be sorted by name, and the other by age.
The arrays seem to be sorting correctly when I output them to the log; however, when I try to access them elsewhere in the code, I'm receiving a EXC_BAD_ACCESS error.
Here's what I have so far:
// MyController.h
#interface MyController : UIViewController {
NSMutableArray *originalArray;
NSMutableArray *nameArray;
NSMutableArray *ageArray;
}
#property (nonatomic, retain) NSMutableArray *originalArray;
#property (nonatomic, retain) NSMutableArray *nameArray;
#property (nonatomic, retain) NSMutableArray *ageArray;
-(void)someRandomMethod;
#end
// MyController.m
#import "MyController.h"
#implementation MyController
#synthesize originalArray;
#synthesize nameArray;
#synthesize ageArray;
-(void)viewDidLoad {
// originalArray = (
// {
// "name" = "Sally";
// "age" = 18;
// },
// {
// "name" = "Chad";
// "age" = 26;
// },
// {
// "name" = "Carla";
// "age" = 24;
// },
// )
// sort by name
NSSortDescriptor *sortByNameDescriptor;
sortByNameDescriptor = [[[NSSortDescriptor alloc]
initWithKey:#"name"
ascending:NO] autorelease];
NSArray *sortByNameDescriptors = [NSArray arrayWithObject:sortByNameDescriptor];
nameArray = [originalArray sortedArrayUsingDescriptors:sortByNameDescriptors];
// sort by age
NSSortDescriptor *sortByAgeDescriptor;
sortByAgeDescriptor = [[[NSSortDescriptor alloc]
initWithKey:#"age"
ascending:NO] autorelease];
NSArray *sortAgeDescriptors = [NSArray arrayWithObject:sortByAgeDescriptor];
ageArray = [originalArray sortedArrayUsingDescriptors:sortByAgeDescriptors];
[super viewDidLoad];
}
-(void)someRandomMethod {
// whenever I try to access the sorted arrays, I receive the EXC_BAD_ACCESS error
[[nameArray objectAtIndex:0] valueForKey:#"name"];
[[ageArray objectAtIndex:0] valueForKey:#"age"];
}
-(void)viewDidUnload {
self.originalArray = nil;
self.nameArray = nil;
self.ageArray = nil;
[super viewDidUnload];
}
- (void)dealloc {
[originalArray release];
[nameArray release];
[ageArray release];
[super dealloc];
}
#end
Any ideas?
UPDATE: Thanks to #robin, by changing the code above to the code below, everything works great:
// sort by name
NSSortDescriptor *sortByNameDescriptor;
sortByNameDescriptor = [[[NSSortDescriptor alloc]
initWithKey:#"name"
ascending:NO] autorelease];
NSArray *sortByNameDescriptors = [NSArray arrayWithObject:sortByNameDescriptor];
nameArray = [[NSMutableArray alloc] initWithArray:[originalArray sortedArrayUsingDescriptors:sortByNameDescriptors]];
// sort by age
NSSortDescriptor *sortByAgeDescriptor;
sortByAgeDescriptor = [[[NSSortDescriptor alloc]
initWithKey:#"age"
ascending:NO] autorelease];
NSArray *sortAgeDescriptors = [NSArray arrayWithObject:sortByAgeDescriptor];
ageArray = [[NSMutableArray alloc] initWithArray:[originalArray sortedArrayUsingDescriptors:sortByAgeDescriptors]];
I dont think you know about this or not but when ever you create an object like string or array or dictionary, with init methods then the retain count gets incremented by 1
and if you create them like this
NSArray *anarray = [NSArray arrayWithArray:temp];
this will create an autorelease objects that will be released automatically after sometime.
So my advice don't use this type of code if you want to use the objects in more than 1 function. Always use init methods first to get the work done.
and if you are sure that the objects are not needed for the rest of the program than release them using release methode.
Related
My array is not saving the values I put in it...
I am defining my nsmutablearray *arrayClientList in .h file
#interface StartupTableViewController : UIViewController<UITableViewDataSource, UITableViewDelegate>
#property (strong, nonatomic) IBOutlet UITableView *tableView;
#property NSMutableArray *arrayClientList;
#property BOOL boolAddToClient;
//#property (strong, nonatomic) NSMutableArray *arrayAddClient;
#end
in .m file I am initializing like so
- (void)viewDidLoad {
[super viewDidLoad];
//initialize variables
self.arrayClientList = [[NSMutableArray alloc] init];
arraySelectedInformation = [[NSMutableArray alloc] init];
self.boolAddToClient = NO;
NSString *tstring = #"hello";
[self.arrayClientList addObject:tstring];
but then once I get to another method in this same class... the array is nil again. I must be doing something stupid for the array not to hold the values
-(void)viewDidAppear:(BOOL)animated{
//NSLog(#"appeared");
if (self.boolAddToClient) {
NSLog(#"add client to list");
self.boolAddToClient = NO;
[self.tableView reloadData];
}
else{
NSLog(#"startup");
}
}
I am trying to use it in another class
- (IBAction)buttonSubmit:(id)sender {
NSString *userDescription = [[NSString alloc] init];
NSString *userUsername = [[NSString alloc] init];
NSString *userPassword = [[NSString alloc] init];
userDescription = self.textfieldDescription.text;
userUsername = self.textfieldUserID.text;
userPassword = self.textfieldPW.text;
//check to make sure user filled out all fields
if (![userDescription isEqual:#""] && ![userUsername isEqual:#""] && ![userPassword isEqual: #""]){
NSLog(#"correct");
NSArray *arrayVC = self.navigationController.viewControllers;
StartupTableViewController *parentViewController = [arrayVC objectAtIndex:0];
parentViewController.boolAddToClient = YES;
NSMutableArray *arrayNewObjects = [[NSMutableArray alloc] initWithObjects:userDescription, userUsername, userPassword, nil];
NSMutableArray *tarray = parentViewController.arrayClientList;
[tarray addObject:arrayNewObjects];
[parentViewController.arrayClientList addObject:arrayNewObjects];
[self.navigationController popViewControllerAnimated:YES];
}
else{
NSLog(#"something missing");
}
}
Since I can't comment without rep, I must try with answer.
Try this:
In ViewDidLoad do alloc init with Strings you create in implementation and also change if block to this:
#implementation
{
NSString *userDescription;
NSString *userUsername;
NSString *userPassword;
}
-(void)viewDidLoad {
[super viewDidLoad];
NSString *userDescription = [[NSString alloc] init];
NSString *userUsername = [[NSString alloc] init];
NSString *userPassword = [[NSString alloc] init];
}
- (IBAction)buttonSubmit:(id)sender {
if (self.textfieldDescription.text.lenght != 0 && self.textfieldUserID.text.lenght != 0 && self.textfieldPW.text.lenght != 0) {
userDescription = self.textfieldDescription.text;
userUsername = self.textfieldUserID.text;
userPassword = self.textfieldPW.text;
....... and the rest
}
Please comment if it's not working, and I also think that you're not passing the informations right. Try searching an answer on how to pass arrays between TableViewControllers. Good Luck!
This question already has answers here:
Cannot add items to an NSMutableArray ivar
(4 answers)
Closed 8 years ago.
I'm trying to add NSMutableArray to other NSMutableArray, a mutable array set as instance ivar, but I allways got the array arrayPlayoff empty. Other thing that I have detected, is that when debugging in the attached method, local variables are not shown in the debugger variables section, even selecting "local" option.
-(void)loadGamesPlayoffs{
NSMutableArray *eli1 = [[NSMutableArray alloc] init];
NSMutableArray *eli2 =[[NSMutableArray alloc] init];
NSMutableArray *eli3 = [[NSMutableArray alloc] init];
NSMutableArray *eli4 = [[NSMutableArray alloc] init];
for (NSDictionary *eliminatoria in copaReyArray){
int eli = [[eliminatoria valueForKey:#"eliminatoria"]integerValue];
NSLog(#"eli %d", eli);
if (eli==1){
[eli1 addObject:eliminatoria];
} else if (eli==2){
[eli2 addObject:eliminatoria];
}else if (eli==3){
[eli3 addObject:eliminatoria];
} else if (eli==4){
[eli4 addObject:eliminatoria];
}
}
[arrayPlayOff addObject:eli1];
[arrayPlayOff addObject:eli2];
[arrayPlayOff addObject:eli3];
[arrayPlayOff addObject:eli4];
}
many thanks
If arrayPlayOff is an Instance Variable you could use properties, your .h should look something like this:
#import <UIKit/UIKit.h>
#interface YourClassViewController : UIViewController{
NSMutableArray *arrayPlayOff;
//Some other variables
}
#property (nonatomic, retain) NSMutableArray *arrayPlayOff;
//Some other methods
#end
Then in your .m file you could use:
#implementation YourClassViewController
#synthesize arrayPlayOff;
- (NSMutableArray *)arrayPlayOff{
if(!arrayPlayOff){
arrayPlayOff = [[NSMutableArray alloc] init];
}
return arrayPlayOff;
}
//Your other methods
//Overwrite the dealloc function so you don't have any memory leaks
- (void)dealloc{
[arrayPlayOff release];
[super dealloc];
}
#end
Now you could access your variable as
self.arrayPlayOff
and this way you can be 100% sure that your variable is always initialized.
Your method could look like this (Also you should release your other NSMutableArrays since you are not using after adding them to the arrayPlayOff array):
-(void)loadGamesPlayoffs{
NSMutableArray *eli1 = [[NSMutableArray alloc] init];
NSMutableArray *eli2 =[[NSMutableArray alloc] init];
NSMutableArray *eli3 = [[NSMutableArray alloc] init];
NSMutableArray *eli4 = [[NSMutableArray alloc] init];
for (NSDictionary *eliminatoria in copaReyArray){
int eli = [[eliminatoria valueForKey:#"eliminatoria"]integerValue];
NSLog(#"eli %d", eli);
if (eli==1){
[eli1 addObject:eliminatoria];
} else if (eli==2){
[eli2 addObject:eliminatoria];
}else if (eli==3){
[eli3 addObject:eliminatoria];
} else if (eli==4){
[eli4 addObject:eliminatoria];
}
}
[self.arrayPlayOff addObject:eli1];
[self.arrayPlayOff addObject:eli2];
[self.arrayPlayOff addObject:eli3];
[self.arrayPlayOff addObject:eli4];
//Releasing the NSMutableArrays
[eli1 release];
[eli2 release];
[eli3 release];
[eli4 release];
}
I want to use a variable-sized multi-dimensional array in my app to save data. The data structure I want to use is as below, the first element in each row is followed by corresponding multiple values.
array = { {a, a_val1, a_val2, a_val3}.
{b, b_val1},
{c, c_val1, c_val2, c_val3, c_val4, c_val5}
}
Any idea how I can implement in objective-c?
use NSMutableArray like so
NSMutableArray *curRow; /* use to access the row while loading with objects */
NSMutableArray *array = [[NSMutableArray alloc] init]; /* your main multidim array */
curRow = [NSMutableArray array];
[curRow addObject:/* what you want here */];
[curRow addObject:/* what you want here */];
[curRow addObject:/* what you want here */];
[array addObject:curRow]; /* first row is added */
/* rinse and repeat */
curRow = [NSMutableArray array];
[curRow addObject:/* what you want here */];
[curRow addObject:/* what you want here */];
[curRow addObject:/* what you want here */];
[array addObject:curRow];
use NSMutableArray
Below is the example for your understanding ...
NSMutableArray * multiArray = [[NSMutableArray alloc] initWithCapacity:5];
[multiArray addObject:[NSArray arrayWithObjects:a,a_val1,a_val2]];
[multiArray addObject:[NSArray arrayWithObjects:a,a_val1,a_val2,a_val3,a_val4]];
[multiArray addObject:[NSArray arrayWithObjects:a,a_val1,a_val5]];
[multiArray addObject:[NSArray arrayWithObjects:a,a_val1,a_val2,a_val3,a_val4,a_val5,a_val6]];
And Don't forget to release to multiArray array because we have alloced it ...
Objective-C does not have a real 2 dimensional array type but you can implement it with the
following codes..
in your header file --- yourheader.h
#import <Foundation/Foundation.h>
#interface yourheader : NSObject{
NSMutableDictionary* DictionaryArrayType;
NSMutableArray* MultiArrayType;
NSArray* CaptionTitle;
NSArray* ObjectValue;
}
#property (strong, nonatomic) NSMutableDictionary* DictionaryArrayType;
#property (strong, nonatomic) NSArray* CaptionTitle;
#property (strong, nonatomic) NSArray* ObjectValue;
#property (strong, nonatomic) NSMutableArray* MultiArrayType;
-(id) AddArrayObjects:(NSString*)_Name : (NSString*)_Surname :(NSString*)_Age;
-(id) AddArrayDictionaryObject:(NSArray*)_ArrayObject : (NSArray*)_ArrayKey;
-(id) AddMultiArrayType:(id)_ArrayObject;
-(void) ShowMultiArrayType:(id)_ArrayObject;
#end
Now add to your objective-c file ---- objective-c.m
#import "yourheader.h"
#implimentation yourheader
#synthesize DictionaryArrayType;
#synthesize CaptionTitle;
#synthesize ObjectValue;
#synthesize MultiArrayType;
-(id)init {
if(self = [super init]){
NSString* const NAME = #"NAME";
NSString* const SURNAME = #"SURNAME";
NSString* const AGE = #"AGE";
//Adding fixed content to CaptionTitle Array
[self setCaptionTitle:[NSArray arrayWithObjects:NAME, SURNAME, AGE, nil]];
//add values to ObjectValue array
[self AddArrayObjects:#"Bob" :#"Obi" :#"200"];
//add values to dictionary
[self AddDictionaryArrayType:ObjectValue :CaptionTitle];
//Add to the Multi dimensional array [][]
[self AddMultiArrayType:DictionaryArrayType];
//add the second row values to ObjectValue array
[self AddArrayObjects:#"Barack" :#"Obama" :#"50"];
//add values to dictionary
[self AddDictionaryArrayType:ObjectValue :CaptionTitle];
//Add to the Multi dimensional array [][]
[self AddMultiArrayType:DictionaryArrayType];
//display the 2d Array
[self ShowMultiArrayType:MultiArrayType];
}
return self;
}
-(id)AddArrayObjects:(NSString *)_name :(NSString *)_surname :(NSString *)_age {
//Set the Array Objects;
[self setObjectValue:[NSArray arrayWithObjects:_name, _surname, _age, nil]];
return self;
}
-(id)AddDictionaryArrayType:(NSArray *)_ArrayObject :(NSArray*)_ArrayKey {
if(!DictionaryArrayType) {
//initialize disctionary
[self setDictionaryArrayType:[NSMutableDictionary dictionary]];
}
//add array obeject and Fixed Key decleared in CaptionTitle array
DictionaryArrayType = [NSMutableDictionary dictionaryWithObjects:_ArrayObject forKeys:_ArrayKey];
return self;
}
-(id) AddMultiArrayType:(id)_ArrayObject {
if(!MultiArrayType) {
[self setMultiArrayType:[NSMutableArray array]];
}
[MultiArrayType addObject:_ArrayObject];
return self;
}
-(void)ShowMultiArrayType:_ArrayObject {
for(id objects in _ArrayObject ) {
for(id key in objects) {
NSLog(#"%# key = : object = %#", key, [objects objectForKey:key]);
}
}
}
#end;
To finish add this to your appdelegate.m file inside the app
yourclassname* _yourclasspointer = [[yourclassname alloc] init];
[_youclasspointer ShowMultiArrayType:[_yourclasspointer MultiArrayType]];
You should see it in you console.
.h
#property (nonatomic, retain) NSArray *m_plistData;
.m
#synthesize m_plistData;
- (void)viewDidLoad
{
NSArray *array = [[NSArray alloc]initWithObjects:#"0",#"1",#"2",#"3",#"4",#"5",#"6",#"7",#"8",#"9",#"10",#"11",#"12",#"13",#"14", nil];
m_plistData = array;
NSArray *nn = m_plistData;
[super viewDidLoad];
}
I use breakpoint and found array is normal,but m_plistData has no values,shows "out of scope",I can't understand why nn can get normal values
array is a local reference variable. It just lasts until viewDidLoad method. Now,
m_plistData = array;
The above statement doesn't make a deep copy. It is just a shallow copy.
- (void)viewDidLoad
{
NSArray *array = [[NSArray alloc]initWithObjects:#"0",#"1",#"2",#"3",#"4",#"5",#"6",#"7",#"8",#"9",#"10",#"11",#"12",#"13",#"14", nil];
m_plistData = array;
NSArray *nn = m_plistData;
[super viewDidLoad];
} // Both the array, nn references cease to exist after this point.
// So having references to it leads to run-time exception if used else where.
If your objective is have elements in m_plistData, directly do -
m_plistData = [[NSArray alloc]initWithObjects:#"0",#"1",#"2",#"3",#"4",#"5",#"6",#"7",#"8",#"9",#"10",#"11",#"12",#"13",#"14", nil];
Try something like:
m_plistData = [array copy];
Do it like this as you have a NSAarray:
if(array)
{
m_plistData = [NSArray arrayWithArray:array];
}
I am trying to access and change a array from a different class file. When using a NSLog, I get a result of (null). Below is my code:
RootViewController.h
NSMutableArray *listOfItems;
#property (nonatomic, retain) NSMutableArray *listOfItems;
RootViewController.m
#synthesize listOfItems;
listOfItems = [[NSMutableArray alloc] init];
[listOfItems addObject:#"One"];
[listOfItems addObject:#"Two"];
[listOfItems addObject:#"Three"];
SecondViewController.m
RootViewController *test = [[RootViewController alloc] init];
NSLog(#"Results: %#", test.listOfItems);
I get the following results in my console: Results: (null)
Thanks in advance,
Coulton
P.S. Obviously I have left out a bunch of code. I just tried to make it easier to read. If you need to see anything else, I would be more than happy to post more. Just ask
EDIT #1:
I am getting hundreds of NSLog Messages that look something like this:
*** __NSAutoreleaseNoPool(): Object 0x4e39020 of class __NSArrayI autoreleased with no pool in place - just leaking
And here's my init code:
- (id) init {
//NSLog(#"%#", theUserID);
// Set up database connection
NSString *myDB = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"database.db"];
database = [[Sqlite alloc] init];
[database open:myDB];
//Initialize the array.
listOfItems = [[NSMutableArray alloc] init];
// Add to array to display in the tableView
NSArray *listOfItemsTwo = [database executeQuery:#"SELECT * FROM albums"];
for (NSDictionary *rowone in listOfItemsTwo) {
NSString *getName = [rowone valueForKey:#"name"];
if (getName != NULL) {
[listOfItems addObject:getName];
[getName release];
}
}
return self;
}
I guess you reversed RootViewController.m and RootViewController.h snippets right?
Are you sure that the
listOfItems = [[NSMutableArray alloc] init];
gets called? Maybe you can put a breakpoint there.
EDIT: Order of RootViewController.m and RootViewController.h has been fixed in the question. It's not clear from the question where the above line is in the code. That's a important piece of information.
EDIT2: Example of init method.
#implementation RootViewController
- (id) init
{
listOfItems = [[NSMutableArray alloc] init];
[listOfItems addObject:#"One"];
return self;
}
#end