Displaying Array and Dictionary values in a tableview - ios

Question

I have created an array, two dictionaries and a tableview. The tableview should display the contents of array and that array contains the data of dictionaries. When i try to display it using "[mArray addObject:(mDictionary)];" its throwing an exception but if i use "[mArray addObject:[mDictionary objectForKey:#"firstname"]];" its working fine.
Can you help me to understand why is it happening and isn't it possible to display the dictionary value without using "objectForKey"?
Here is my "ViewController.m".
#import "ViewController.h"
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
mArray = [[NSMutableArray alloc]init];
mDictionary = [[NSMutableDictionary alloc]init];
[mDictionary setValue:#"shanu" forKey:#"firstname"];
[mDictionary setValue:#"kumar" forKey:#"lastname"];
mDictionary2 = [[NSMutableDictionary alloc]init];
[mDictionary2 setValue:#"hgjghjgf" forKey:#"firstname1"];
[mDictionary2 setValue:#"ghjgjgfj" forKey:#"lastname1"];
[mArray addObject:mDictionary];
[mArray addObject:mDictionary2];
CGRect frame = self.view.frame;
UITableView *tableView = [[UITableView alloc]initWithFrame:frame style:UITableViewStylePlain];
tableView.separatorStyle = UITableViewCellSeparatorStyleSingleLine;
tableView.backgroundColor = [UIColor cyanColor];
tableView.separatorColor = [UIColor blackColor];
tableView.delegate = self;
tableView.dataSource = self;
[self.view addSubview:tableView];
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
return #"Array and Tableview";
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return mArray.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell"];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"];
}
cell.textLabel.text = [mArray objectAtIndex:indexPath.row];
return cell;
}
- (void)dealloc
{
[mArray release];
[mDictionary release];
[mDictionary2 release];
[super dealloc];
}
#end

Answer 1

Declare an array in .h file:
NSArray *keys
write this in viewDidLoad
keys = [mDictionary allKeys];
This in cellForRowAtIndexPath
cell.textLabel.text = [mDictionary objectForKey:[keys objectAtIndex:indexPath.row];

Answer 2

If you try to assign the some text to the cell's textlabel the object returned from:
[mArray objectAtIndex:indexPath.row];
should be a string and not a whole dictionary.
When you just put the whole dictionary in the array [mArray objectAtIndex:indexPath.row]; will return a dictionary and you cannot assign a dictionary to the textlabel so you get an exception. If you want to store the whole dictionary use objectForKey to get the string you want:
cell.textLabel.text = [[mArray objectAtIndex:indexPath.row] objectForKey:#"WHAT_EVER_KEY_YOU_WANT"];
btw, you are not using ARC zo you probably want to get an autoreleased UITableViewCell so add autorelease to you cell:
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"] autorelease];
or
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"];
[cell autorelease];

Answer 3

Array contains similar type objects. You can add dictionary objects into array. There is no problem in that case. The problem is when you get an element from array and assign to cell.textLabel.text. Here object is type of dictionary and cell.textLabel.text is type of nsstring. So you should assign a value for key of dictionary object into cell.textLabel.text.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell"];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"];
}
cell.textLabel.text = [[mArray objectAtIndex:indexPath.row] objectForKey:#"firstname"];
cell.detialTextLabel.text = [[mArray objectAtIndex:indexPath.row] objectForKey:#"lastname"];
return cell;
}
I think it will be helpful to you.

Answer 4

This solved my problem
NSDictionary *cellDict = [self.tableInfoArr objectAtIndex:indexPath.row];
//This is to don't care about what is key and value in that dictionary
NSArray *keyArr = [cellDict allKeys];
//As at each index of array only one dictionary exist.
NSString *keyStr = [keyArr objectAtIndex:0];
cell.titleLabel.text = keyStr;
cell.detailLabel.text = [cellDict valueForKey:keyStr];