objective-c multi-dimensional array - objective-c

Question

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?

Answer 1

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];

Answer 2

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 ...

Answer 3

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.