Dictionary retrieval of value for key IOS - objective-c

Question

I am sorry i am new to IOS,i couldnt figure out the solution to this problem
This is just a beginner restaurant menu
There is a tableview containing items and price and when i click one item,it displays another view where the user has to input the quantity and click a done button,so when the user clicks done i want to multiply the quantity times the price,how do i retrieve that particular price and multiply it with the quantity user input in the textfield.
Here's my code
I have declared NSDictionary in the Menu header file called
NSDictionary *dict;
My viewdidload method
dict=[[NSDictionaryalloc]initWithObjectsAndKeys:
#"TomatoSoup",#"20.00",#"VegManchowSoup",#"12.00",nil];
NSLog(#"%#",dict);
[super viewDidLoad];
I have displayed this contents in a table view
- (NSInteger)tableView:(UITableView *)table numberOfRowsInSection:(NSInteger)section{
return [[dict allKeys]count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
NSArray *sortedkeys=[[dict allKeys]sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
NSString *key=[sortedkeys objectAtIndex:indexPath.row];
NSString *value=[dict objectForKey:key];
cell.textLabel.text=value;
cell.detailTextLabel.text=key;
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath{
if(indexPath.row==0){
VegQuantity *vegetarian1 = [[VegQuantity alloc] initWithNibName:#"VegQuantity" bundle:nil];
vegetarian1.m_SelectedIndexPath=indexPath.row;
vegetarian1.pass=dict;
[self presentModalViewController:vegetarian1 animated:YES];
}
if(indexPath.row==1){
VegQuantity *vegetarian1 = [[VegQuantity alloc] initWithNibName:#"VegQuantity" bundle:nil];
vegetarian1.m_SelectedIndexPath=indexPath.row;
[self presentModalViewController:vegetarian1 animated:YES];
}
}
VegQuantity.h
There is a View that has a textfield and a button saying done,
now when I click the done button I need to retrieve the value for that particular soup and multiply it with the number of quantity I input.
My problem is how am I supposed to retrieve the price(value) for that particular key and multiply it with the quantity.

Answer 1

dict=[[NSDictionary alloc]initWithObjectsAndKeys:
#"TomatoSoup",#"20.00",#"VegManchowSoup",#"12.00",nil];
The method is initWithObjectsAndKeys, which means first is the object then key, (key "20.00", object - "TomatoSoup") - in your case it's the opposite.
Second, instead of having an NSString for the price (I suppose it's price or quantity) use NSNumber - [NSNumber numberWithFloat:20.0f].
Then, make your VegQuantity view controller (btw it's good idea to call it VegQuantityViewController, in order to keep the naming conventions) 2 properties:
#property (nonatomic, strong) NSString *itemName; //Use strong if using ARC, otherwise retain
#property (nonatomic, strong) NSNumber *price;
and pass those values to the view controller before you show it. Then inside it you can do whatever you want with them.
P.S. It's a good practice to use properties to manipulate the values of the instance variables.

Answer 2

You retrieve a value from a Dictionary by using.
[dict objectForKey:#"someDummyKey"];
But to be honest. You should use a NSMutableArray as datasource for you UITableView and not a NSDictionary.