I have an NSMutableDictionary with some values in it, and I need to join the keys and values into a string, so
> name = Fred
> password = cakeismyfavoritefood
> email = myemailaddress#is.short
becomes name=Fred&password=cakeismyfavoritefood&email=myemailaddress#is.short
How can I do this? Is there a way to join NSDictionaries into strings?
You can easily do that enumerating dictionary keys and objects:
NSMutableString *resultString = [NSMutableString string];
for (NSString* key in [yourDictionary allKeys]){
if ([resultString length]>0)
[resultString appendString:#"&"];
[resultString appendFormat:#"%#=%#", key, [yourDict objectForKey:key]];
}
Quite same question as Turning a NSDictionary into a string using blocks?
NSMutableArray* parametersArray = [[NSMutableArray alloc] init];
[yourDictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
[parametersArray addObject:[NSString stringWithFormat:#"%#=%#", key, obj]];
}];
NSString* parameterString = [parametersArray componentsJoinedByString:#"&"];
[parametersArray release];
Related
I have an NSMutableArray that looks like this
{
"#active" = false;
"#name" = NAME1;
},
{
"#active" = false;
"#name" = NAME2;
}
Is there a way to convert this to an NSDictionary and then use objectForKey to get an array of the name objects? How else can I get these objects?
There is a even shorter form then this proposed by Hubert
NSArray *allNames = [array valueForKey:#"name"];
valueForKey: on NSArray returns a new array by sending valueForKey:givenKey to all it elements.
From the docs:
valueForKey:
Returns an array containing the results of invoking
valueForKey: using key on each of the array's objects.
- (id)valueForKey:(NSString *)key
Parameters
key The key to retrieve.
Return Value
The value of the retrieved key.
Discussion
The returned array contains NSNull elements for each object that returns nil.
Example:
NSArray *array = #[#{ #"active": #NO,#"name": #"Alice"},
#{ #"active": #NO,#"name": #"Bob"}];
NSLog(#"%#\n%#", array, [array valueForKey:#"name"]);
result:
(
{
active = 0;
name = Alice;
},
{
active = 0;
name = Bob;
}
)
(
Alice,
Bob
)
If you want to convert NSMutableArray to corresponding NSDictionary, just simply use mutableCopy
NSMutableArray *phone_list; //your Array
NSDictionary *dictionary = [[NSDictionary alloc] init];
dictionary = [phone_list mutableCopy];
This is an Array of Dictionary objects, so to get the values you would:
[[myArray objectAtIndex:0]valueForKey:#"name"]; //Replace index with the index you want and/or the key.
This is example one of the exmple get the emplyee list NSMutableArray and create NSMutableDictionary.......
NSMutableArray *emloyees = [[NSMutableArray alloc]initWithObjects:#"saman",#"Ruchira",#"Rukshan",#"ishan",#"Harsha",#"Ghihan",#"Lakmali",#"Dasuni", nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *word in emloyees) {
NSString *firstLetter = [[word substringToIndex:1] uppercaseString];
letterList = [dict objectForKey:firstLetter];
if (!letterList) {
letterList = [NSMutableArray array];
[dict setObject:letterList forKey:firstLetter];
}
[letterList addObject:word];
} NSLog(#"dic %#",dict);
yes you can
see this example:
NSDictionary *responseDictionary = [[request responseString] JSONValue];
NSMutableArray *dict = [responseDictionary objectForKey:#"data"];
NSDictionary *entry = [dict objectAtIndex:0];
NSString *num = [entry objectForKey:#"num"];
NSString *name = [entry objectForKey:#"name"];
NSString *score = [entry objectForKey:#"score"];
im sorry if i can't elaborate much because i am also working on something
but i hope that can help you. :)
No, guys.... the problem is that you are stepping on the KeyValue Mechanism in cocoa.
KeyValueCoding specifies that the #count symbol can be used in a keyPath....
myArray.#count
SOOOOOO.... just switch to the ObjectForKey and your ok!
NSMutableDictionary *myDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:#"theValue", #"#name", nil];
id kvoReturnedObject = [myDictionary valueForKey:#"#name"]; //WON'T WORK, the # symbol is special in the valueForKey
id dictionaryReturnedObject = [myDictionary objectForKey:#"#name"];
NSLog(#"object = %#", dictionaryReturnedObject);
can someone explain to me why [tweets count]; is equal to 1 please? the finalDict atm only has one dictionary, but arrayForLetter has 6 and in each of them some values. how do i get all 6 dictionaries from arrayForLetter ?
NSEnumerator *enumerator = [finalDict keyEnumerator];
id key;
while ((key = [enumerator nextObject])) {
NSDictionary *arrayForLetter = [finalDict objectForKey:key];
NSLog(#"arrayForLetter %#",arrayForLetter);
NSEnumerator *myEnumerator = [arrayForLetter keyEnumerator];
id myKey;
while ((myKey = [myEnumerator nextObject])) {
statuses=[[arrayResults alloc] initWithAppDictionary:arrayForLetter andAppID:myKey];
tweets = [[NSMutableArray alloc] init] ;
[tweets addObject:statuses];
[countryList reloadData];
//NSLog(#"%# : %#", key, [finalDict objectForKey:key]);
}
}
The reason is obvious.. within the while loop you are re-allocating the tweets array and then adding an object. To get count of 6 you need to alloc - init the tweets array before the while loop !
I am having an array like fallowing,
NSArray*array = [NSArray arrayWithObjects:#"1.1 something", #"1.2 something else", #"1.3 out of left field", #"1.4 yet another!", nil];
Now,i am having the string like fallowing,
NSString*str = #"1.3";
Now i will send the str .Then it needs to find that str in array and it need to return the index of object where that text found.Means i need index 2 has to come as output.Can anyone share the code please.Thanks in advance.
Here is an example using blocks, notice the method: hasPrefix:
NSArray *array = [NSArray arrayWithObjects:#"1.1 problem1", #"1.2 problem2", #"1.3 problem3", #"1.4 problem4", nil];
NSString *str = #"1.3";
NSUInteger index = [array indexOfObjectPassingTest:
^(id obj, NSUInteger idx, BOOL *stop) {
return [obj hasPrefix:str];
}];
NSLog(#"index: %lu", index);
NSLog output:
index: 2
First a comment,
NSString *str = 1.3;
does not create an NSString object. You should instead have
NSString *str = #"1.3";
To search the NSArray, you will either have to change the string to the exact string in the array or search the NSString as well. For the former, simply do
float num = 1.3;
NSString *str = [NSString stringWithFormat:#"%.1f problem%d",num,(num*10)%10];
[array indexOfObject:str];
You can get fancier using NSPredicates as well.
Try
NSString *searchString = [str stringByAppendingFormat: #" problem%#", [str substringFromIndex: 2]];
NSUInteger index = [array indexOfObject: searchString];
Or (because you somehow like oneliners):
[array indexOfObject: [[array filteredArrayUsingPredicate: [NSPredicate predicateWithFormat: #"SELF beginswith %#", str]] objectAtIndex: 0]];
The simplest way is to enumerate through values of array and check substrings:
NSArray *array = [NSArray arrayWithObjects: #"1.1 something", #"1.2 something else", #"1.3 out of left field", #"1.4 yet another!", nil];
NSString *str = #"1.33";
int i = -1;
int index = -1;
for (NSString *arrayString in array) {
i++;
if ([arrayString rangeOfString: str].location != NSNotFound) {
index = i;
break;
}
}
NSLog(#"Index: %d", index);
Not optimal but will work.
I have and array of many strings.
I wan't to sort them into a dictionary, so all strings starting the same letter go into one array and then the array becomes the value for a key; the key would be the letter with which all the words in it's value's array begin.
Example
Key = "A" >> Value = "array = apple, animal, alphabet, abc ..."
Key = "B" >> Value = "array = bat, ball, banana ..."
How can I do that?
Thanks a lot in advance!
NSArray *list = [NSArray arrayWithObjects:#"apple, animal, bat, ball", nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *word in list) {
NSString *firstLetter = [[word substringToIndex:1] uppercaseString];
NSMutableArray *letterList = [dict objectForKey:firstLetter];
if (!letterList) {
letterList = [NSMutableArray array];
[dict setObject:letterList forKey:firstLetter];
}
[letterList addObject:word];
}
NSLog(#"%#", dict);
You can achieve what you want through the following steps:
Create an empty but mutable dictionary.
Get the first character.
If a key for that character does not exist, create it.
Add the word to the value of the key (should be an NSMutableArray).
Repeat step #2 for all keys.
Here is the Objective-C code for these steps. Note that I am assuming that you want the keys to be case insensitive.
// create our dummy dataset
NSArray * wordArray = [NSArray arrayWithObjects:#"Apple",
#"Pickle", #"Monkey", #"Taco",
#"arsenal", #"punch", #"twitch",
#"mushy", nil];
// setup a dictionary
NSMutableDictionary * wordDictionary = [[NSMutableDictionary alloc] init];
for (NSString * word in wordArray) {
// remove uppercaseString if you wish to keys case sensitive.
NSString * letter = [[word substringWithRange:NSMakeRange(0, 1)] uppercaseString];
NSMutableArray * array = [wordDictionary objectForKey:letter];
if (!array) {
// the key doesn't exist, so we will create it.
[wordDictionary setObject:(array = [NSMutableArray array]) forKey:letter];
}
[array addObject:word];
}
NSLog(#"Word dictionary: %#", wordDictionary);
Take a look at this topic, they solves almost the same problem as you — filtering NSArray into a new NSArray in objective-c Let me know if it does not help so I will write for you one more code sample.
Use this to sort the contents of array in alphabetical order, further you design to the requirement
[keywordListArr sortUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
I just wrote this sample. It looks simple and does what you need.
NSArray *names = [NSArray arrayWithObjects:#"Anna", #"Antony", #"Jack", #"John", #"Nikita", #"Mark", #"Matthew", nil];
NSString *alphabet = #"ABCDEFGHIJKLMNOPQRSTUWXYZ";
NSMutableDictionary *sortedNames = [NSMutableDictionary dictionary];
for(int characterIndex = 0; characterIndex < 25; characterIndex++) {
NSString *alphabetCharacter = [alphabet substringWithRange:NSMakeRange(characterIndex, 1)];
NSArray *filteredNames = [names filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"SELF BEGINSWITH[C] %#", alphabetCharacter]];
[sortedNames setObject:filteredNames forKey:alphabetCharacter];
}
//Just for testing purposes let's take a look into our sorted data
for(NSString *key in sortedNames) {
for(NSString *value in [sortedNames valueForKey:key]) {
NSLog(#"%#:%#", key, value);
}
}
I'm sure there is a way to do this using blocks, but I cant figure it out. I want to to turn an NSDictionary into url-style string of parameters.
If I have an NSDictionary which looks like this:
dict = [NSDictionary dictionaryWithObjectsAndKeys:#"blue", #"color", #"large", #"size", nil]];
Then how would I turn that into a string that looks like this:
"color=blue&size=large"
EDIT
Thanks for the clues below. This should do it:
NSMutableString *parameterString;
[dict enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
[parameterString appendFormat:#"%#=%#&", key, obj];
}];
parameterString = [parameterString substringToIndex:[string length] - 1];
Quite same solution but without the substring:
NSMutableArray* parametersArray = [[[NSMutableArray alloc] init] autorelease];
[dict enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
[parametersArray addObject:[NSString stringWithFormat:#"%#=%#", key, obj]];
}];
NSString* parameterString = [parametersArray componentsJoinedByString:#"&"];
Create a mutable string, then iterate the dictionary getting each key. Look up the value for that key, and add the key=value& to the string. When you finish that loop, remove the last &.
I presume this is going to be fed through a URL, you will also want to have some method that encodes your strings, in case they contain items like & or +, etc.
NSMutableString* yourString = #"";
for (id key in dict) {
[yourString appendFormat:#"%#=%#&", key, ((NSString*)[dict objectForKey:key])];
}
NSRange r;
r.location = 0;
r.size = [yourString length]-1;
[yourString deleteCharactersInRange:r];