iOS, key => value from NSArray

Question

I've found a lot of documentation about how to code data into a key => value style, but how do i go about extracting the key & value from an array? I'm currently using NSArray .

What i'm after is the obj-c equivlant to php's foreach($array as $k => $v)

Answer 1

What are you looking for is NSDictionary. NSArray is accessible via indexes: 0, 1, 2 etc:

NSDictionary could be accessed like dict[@"key"] or [dict objectForKey:@"key"];

So, accessing NSArray would be:

for( int i = 0; i < [someArray count]-1; i++)
{
    NSLog(@"%@", someArray[i]);
}

while accessing your NSDictionary would be:

for (NSString* key in yourDict) {
    NSLog(@"%@", yourDict[key]);
    //or
    NSLog(@"%@", [yourDict objectForKey:key]);
}

Answer 2

An NSArray is like this :

NSArray *array = @[@"One", @"Two", @"Three"];

//Loop through all NSArray elements
for (NSString *theString in array) {
    NSLog(@"%@", theString);
}

//Get element at index 2
NSString *element = [array objectAtIndex:2];
//Or :
NSString *element = array[2];

If you have an object and you what to find its index in the array (object must be unique in array, otherwise will only return the first found) :

NSUInteger indexOfObject = [array indexOfObject:@"Three"];

NSLog(@"The index is = %lu", indexOfObject);

But if you are working with keys and values, maybe you need a NSDictionary.

An NSDictionary is like this :

NSDictionary *dictionary = @{@"myKey": @"Hello World !",
                             @"other key": @"What's up ?"
                             };

//Loop NSDictionary all NSArray elements
for (NSString *key in dictionary) {
    NSString *value = [dictionary valueForKey:key];
    NSLog(@"%@ : %@", key, value);
}

Answer 3

If u are having NSArray having number of dictionaries then u can get them as below

for(NSDictionary *dict in yourArray)
{
NSLog(@"The dict is:%@",dict);
NSLog(@"The key value for the dict is:%@",[dict objectForKey:@"Name"]);//key can be changed as per ur requirement
}

///(OR)

[yourdict enumerateKeysAndObjectsUsingBlock:^(id key, id object, BOOL *stop) {

NSLog(@"Key -> value of Dict is:%@ = %@", key, object);
}];

Hope it helps you...!