for ( int cnt = 0 ; cnt < nPeople ; cnt++ )
{
ABRecordRef ref = CFArrayGetValueAtIndex(allPeople, cnt);
NSString *firstName = (NSString *)ABRecordCopyValue(ref, kABPersonFirstNameProperty);
NSString *lastName = (NSString *)ABRecordCopyValue(ref, kABPersonLastNameProperty);
NSString *fullName;
/* skipped code at here : code to merge firstName and lastName to fullName. In my country, many of us don't separate first name and last name */
// tempKeyString : NSString variable that has key of fullNameArray value for nameDictionary.
// fullNameArray : to keep some fullName variables for tempKeyString.
if (!tempKeyString) // there's no tempKeyString, a.k.a. it's the first fullName.
{
// it's not important to know about GetUTF8String:fullName. It's for my own language.
tempKeyString = [self GetUTF8String:fullName];
[fullNameArray addObject:fullName];
}
else
{
if ([tempKeyString characterAtIndex:0] == [[self GetUTF8String:fullName] characterAtIndex:0]) // if fullName has the same tempKey with fullNameArray.
{
[fullNameArray addObject:fullName];
}
else // if fullName has different tempKey with fullNameArray.
{
//tempKey : key data for fullNameArray
NSString *tempKey = [tempKeyString substringToIndex:1];
// tempDict : to keep the deep copy of nameDictionary before adding new key.
NSDictionary *tempDict = [nameDictionary mutableDeepCopy];
// add new key (tempKey) with new value (fullNameArray)
// PROBLEM : ALL values (including previous values) in dictionary(nameDictionary) are overwritten to a new value(fullNameArray).
[nameDictionary setObject:fullNameArray forKey:tempKey];
//empties fullNameArray so that it can get the new fullName of the new tempKey.
[fullNameArray removeAllObjects];
//refresh tempKeyString, and add the new fullName.
tempKeyString = [self GetUTF8String:fullName];
[fullNameArray addObject:fullName];
...
}
}
}
I'm trying to make a NSMutableDictionary object from the contacts of my iPhone. Why I make a NSMutableDictionary typed object is that I need indexes for contacts, and it doesn't look easy to make indexes from ABAddressRef typed object directly. I also need to make searching function..
There was no problem when I just coded, but after debugging the only problem makes me crazy. After I apply the array named fullNameArray with the key named tempKey to the namedDictionary, I can find the nameDictionary has all values with them of fullNameArray. All previous data were overwritten! I tried to make a deep copied version of previous nameDictionary before applying fullNameArray and copy it to the newer nameDictionary. However, when I checked the breakpoint at the third line, I can't find the previous data at the tempDict.
I added more codes and comments. It might help more than my explanation.. any questions are pleased!
I tried to find the reason from here - StackOverflow -, and other webpages all the night, but I couldn't find any similar problems.. please help me! Thank you so much in advance!!
The reason why it get emptied is because
[nameDictionary setObject:fullNameArray forKey:tempKey];
here, you set up your dictionary with the object "fullNameArray", then
[fullNameArray removeAllObjects];
remove all the values inside this array, effectively, removing your object in the "nameDictionary", they are the same object, it's not a deep copy of fullNameArray that you store inside your dictionary. Why did you need to store anything into your array anyway? You're only storing 1 value.
[nameDictionary setObject:fullName forKey:tempKey];
will do what you need. Sorry if I mistaken your question, it's quite hard to understand
Related
I am creating an NSMutableDictionary and assigning an NSString (test and test1) to a parameter key.
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
if (test.length) {
dictionary[#"test"] = test;
}
if (test1.length) {
dictionary[#"test1"] = test1;
}
This method does work. However, I am going to eventually have more strings and don't want a bunch of if statements. I don't want the dictionary keys to exist if the string is empty or nil.
Not sure if there is a way around this.
I thought about creating a separate function that accepts an array of key string and array of string values and use a for loop to see if string value is empty. Then, return a dictionary once the for loop ends. However, you can't insert nil into an NSArray
Something like this
- (void)updateDic:(NSMutableDictionary *)dic withString:(NSString *)str {
if (!str || [str isEqualToString:#""]) {
return;
}
dic[str] = str;
}
And then just iterate over all strings and use that method.
What I'd do is create a NSMutableDictionary category, something like this:
NSMutableDictionary+CustomMethods.m:
- (void)setStringIfNotNil:(NSString *)string forKey:(id <NSCopying>)key {
if (!string || !string.length) { return; }
self[key] = string;
}
Then you can use it like this:
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
[dictionary setStringIfNotNil:test forKey:#"test"]
[dictionary setStringIfNotNil:test1 forKey:#"test1"]
There are three ways according to me..
The first one use the category in which you have to write if condition only single time and you can use it in any class of your project.
Second one by making a separate method to do that task(to check string nil or not and adding into the dictionary).
And the third one , just add all in an array and and perform the action in a loop.
The syntax:
dictionary[#"test"] = test
will remove the value from the dictionary if test is nil (it's a difference between the normal -setObject:forKey: method and the -setObject:forKeyedSubcript: which that syntax invokes). However, that will not work for empty strings.
As mentioned in another answer, you could make an NSDictionary category method to check, then call that method instead.
You could also just use the regular dictionary[key] = value syntax, then when you are done, do:
[dictionary removeObjectsForKeys:[dictionary allKeysForObject:#""]];
If it's possible to have the keys repeated, and you don't want an empty string overriding an earlier valid valid, you would have to check each time -- either by the category method, or using a local macro or inline function or local method.
static inline void SetValidVal(NSMutableDictionary *dictionary, NSString *key, NSString *val) {
if (val.length) { dictionary[key] = val; }
}
or
#define MY_SET_VALID_VAL(dictionary, key, val) if ((val).length) dictionary[key] = (val)
If the key names need to be the same as the name of the local variable, you can play other games with macros (this also assumes the local variable name "dictionary":
#define MY_UPDATE_VAL(val) if (val.length) dictionary[##val] = (val)
Then MY_UPDATE_VAL(test1); would expand to:
if (test1.length) dictionary[#"test1"] = test1;
That's a bit magic though and probably not recommended.
Sorry guys, this problem I am running into is pretty trivial. I just can't wrap my head around it so hope someone can help me. Your help is really appreciated. I am getting JSON data through NSURLConnectDelegate with a web API. I get something like this back:
(
{
id = 340
name = Vicent },
{
id = 339
name = Johny },
{
id = 338
name = Eric }
)
and I save it in a NSMutableArray as a global variable. Now, I have a NSSet of "ids". For example:
{
340, 339
}
In the numberOfRowsInSection, I return the set's count. I am trying to load only the ids in the NSSet from the array with the data saved from the webAPI, so I do something like this in cellForRowIndexPath:
for (NSNumber *num in [set allObjects]) {
NSString *newString = [[savedArray objectAtIndex:indexPath.row]
NSString *new = [num stringValue];
if ([new isEqual:newString]) {
}}
How can I just populate the ids I want?
The JSON makes it look like you have an array of dictionaries, which is a reasonable data structure to use as the data source for a table view.
It sounds like you're trying to filter your array to only include the items that are in your set. Is that right?
If so, you could write code that would create a new array containing the subset of your array elements who's ID is also in your set. There are at least a half-dozen ways to do that. One fairly simple approach would be to use the NSArray method indexesOfObjectsPassingTest. You'd pass that method a block of code that would check each array element to see if it's id object was in your set.
That would give you an NSIndexSet with the indexes of the items in your array who's ID are in your set. Then you could use the NSArray method objectsAtIndexes to get an array of only the objects that are also in the set. Something like this (Assuming that your array of dictionaries is called savedArray and your set is called allObjects:
//get the indexes of items in the array savedArray who's id appears in the set allObjects
NSIndexSet *indexes = [savedArray indexesOfObjectsPassingTest:
^(NSDictionary *obj,
NSUInteger idx,
BOOL *stop)
{
return [allObjects member: obj[#"id"]] != nil;
}
];
//Now build an (immutable) array of just the objects who's ID are in the set
NSArray *subArray = [savedArray objectsAtIndexes: indexes];
The array subArray created above is immutable. If you need a mutable array you would need to make a mutable copy, which is a one-line change.
Disclaimer: I still struggle a little with block syntax, so the above might not be exactly correct, but it gives you the general idea.
I have a generic person object with properties personName, lastName, and age. I am storing the user input into an NSMutableArray and I wanted to find a under by his/her name in the array. I have tried finding a bunch of different solutions but none that quite really work.
This is my main.m
#autoreleasepool {
char answer;
char locatePerson[40];
//Create mutable array to add users for retrieval later
NSMutableArray *people = [[NSMutableArray alloc] init];
do{
Person *newPerson = [[Person alloc]init];
[newPerson enterInfo];
[newPerson printInfo];
[people addObject:newPerson];
NSLog(#"Would you like to enter another name?");
scanf("\n%c", &answer);
}while (answer == 'y');
NSLog(#"Are you looking for a specific person?");
scanf("%c", locatePerson);
//This is where I need help
int idx = [people indexOfObject:]
}
This is very basic but I am new to objective-c and I wanted to try and find the user by name. The solutions I've seen have used the indexesOfObjectsPassingTest method. But I was wondering if I can't just use the indexOfObjectmethod the way I did there to locate a person by its name?
Any help is appreciated.
This is one of those hard problems you should avoid with some up-front design. If you know that you are putting things into a collection class and will need to get them out again based on some attribute (rather than by order of insertion) a dictionary is the most efficient collection class.
You can use a NSDictionary keyed with Person's name attribute. You can still iterate over all the objects but you will avoid having to search the whole collection. It can take a surprisingly long time to find a matching attribute in a NSArray! You wouldn't even have to change your Person object, just do
NSDictionary *peopleDictionary = #{ person1.name : person1, person2.name : person2 };
or add them one by one as they are created into a NSMutableArray.
You can try something like this assuming that 'name' is a property for your Person class.
NSUInteger i = 0;
for(Person *person in people) {
if([person.name isEqualToString:locatePerson]) {
break;
}
i++;
}
I have the following type of a NSMutableDictionary
(
{
id = 1;
key = value;
key = value;
},
{
id = 2;
key = value;
key = value;
}
)
It contains multiple data of an own Object. Now, in cellForRowAtIndexPath. I created a CustomCell that has a field CustomCell.customObject that should get this object. What I'm trying to do is the following. I want to assign the current entry of the NSMutableDictionary to this field.
Alternatively I could do this (and am doing it right now)
I'm getting the ID like this
NSString *objectId = [[dict valueForKey:#"id"] objectAtIndex:indexPath.row];
And then I'm loading the object from the database. The problem I'm seeing in this, is the doubled request. I mean, I already have the data in my NSMutableDictionary, so why should I request it again?
I don't want to just assign a certain key-value pair, I want to assign the whole current object entry of the NSMutableDictionary. How would I do this?
If the above code (dictionary) is used to show information on tableview there is a mistake in it dictionary should always starts with "Key" not with index. So better make the dictionary to array and then you will have index to get complete information in indexes write this code
NSLog(#"%#",[[newArray objectAtIndex:0]objectForKey:#"id"]);
Hope this will help..
I have an NSMutableArray that contains objects of type Person. The Person object contains parameters of NSString *name, NSString *dateStamp, and NSString *testScore. What I would like to do using fast enumeration, is to check to see in the NSMutableArray *testResults, is see if an object with the same name parameter exists.
If it does, then I want to replace the existing object in the NSMutableArray, with the object that I am about to insert which will have the most current dateStamp, and testScore values. If an object with no matching name parameter is found, then simply insert the object that I have.
My code so far looks like this:
This is the code that creates my object that I am about to insert:
Person *newPerson = [[Person alloc] init];
[newPerson setPersonName:newName]; //variables newName, pass, and newDate have already been
[newPerson setScore:pass]; //created and initialized
[newPerson setDateStamp:newDate];
and here is the code where I try to iterate through the NSMutableArray to see if an object with the same name parameter already exists:
for (Person *checkPerson in personList) { //personList is of type NSMutableArray
if (newPerson.newName == checkPerson.name) {
//here is where I need to insert the code that replaces checkPerson with newPerson after a match has been found
}
else {
personList.addObject(newPerson); //this is the code that adds the new object to the NSMutableArray when no match was found.
}
}
It's not a very complicated problem, but I am confused as to how to go about finding a match, and then replacing the actual object without knowing ahead of time what index the object resides in.
You want to use indexOfObjectPassingTest to look for a match:
NSInteger indx = [personList indexOfObjectPassingTest:^BOOL(Person *obj, NSUInteger idx, BOOL *stop) {
return [obj.name isEqualToString:newPerson.name];
}];
if (indx != NSNotFound) {
[personList replaceObjectAtIndex:indx withObject:newPerson];
}else{
[personList addObject:newPerson];
}
Notice that I used isEqualToString: to compare the two strings not ==. That mistake has been asked about and answered a million times on this forum.
You have some inconsistency in your naming. In the question, you say the Person objects have a name property, but when you create a new person you use setPersonName, which would imply that the property name is personName. I assumed, just name in my answer.