NSArray full of NSDictionaries. How to find index of object? - iphone

I have an array which is filled with NSDictionaries. I want to find the index of one of the dictionary, but what I know about this dictionary is only a value for key #"name".
How do I do it ?

Find index of first dictionary in theArray whose value for #"name" is theValue:
NSUInteger index = [theArray indexOfObjectPassingTest:
^BOOL(NSDictionary *dict, NSUInteger idx, BOOL *stop)
{
return [[dict objectForKey:#"name"] isEqual:theValue];
}
];
index will be NSNotFound if no matching object is found.

NSArray *temp = [allList valueForKey:#"Name"];
NSInteger indexValue = [temp indexOfObject:YourText];
NSString *name = [[allList objectAtIndex:indexValue] valueForKey:#"Name"]

Related

Search String into NSArray based on charcters order?

My Problem Scenario is like this. I have an NSMutableArray ( Every Object is Nsstring). I have a UItextField ( as Client said) for Search.
I want know how to Search String into NSMutableArray like this
if I type A into textfield only those Content come from NSMutableArray which start From A.
if I type AB into TextField only those Content Comes from NSMutableArray which is started from AB..
....
I am Trying NSRange Concept I like share Mycode
~
for (int i=0; i<[[localTotalArrayForAwailable objectForKey:#"PUNCH"] count]; i++)
{
NSString *drinkNamePuch= [[[localTotalArrayForAwailable objectForKey:#"PUNCH"] objectAtIndex:i] drinkNames];
NSRange titleResultsRange = [drinkNamePuch rangeOfString:searchText options:( NSCaseInsensitiveSearch)];
if (titleResultsRange.length>0)
{
[searchArraypuch addObject:[[localTotalArrayForAwailable objectForKey:#"PUNCH"] objectAtIndex:i]];
[copyListOfItems setValue:searchArraypuch forKey:#"PUNCH"];
}
}
~
Based on this code search not working proper as i need.
Thanks
If you're trying to find all of the strings that match your searchText from the beginning, then you should check:
if ( titleresultsRange.location == 0 )
Other than that, I am not sure what is "not working proper", you need to provide a better explanation of what your expected results are, and what your actual results are.
Do this;
NSPredicate* predicate = [NSPredicate predicateWithFormat:#"SELF BEGINSWITH[cd] %#", searchText];
NSArray* filteredStrings = [[localTotalArrayForAwailable objectForKey:#"PUNCH"] filteredArrayUsingPredicate:predicate];
In filteredStrings you got all the strings that begins with searchText.
You might find Predicate Programming Guide helpful.
try this logic....it is working
NSMutableArray *arr = [[NSMutableArray alloc]initWithObjects:#"aa",#"bbb",#"bb",#"cc",#"dd",#"ee",#"ff",#"gg",#"hh",#"ii", nil];
NSMutableArray *arrNew = [[NSMutableArray alloc]init];
NSString *strSearch = #"cccc";
int k = strSearch.length;
for (int i=0; i<[arr count]; i++) {
for (int j=0; j<k; j++) {
if (k<=[[arr objectAtIndex:i] length]) {
if ([strSearch characterAtIndex:j] != [[arr objectAtIndex:i]characterAtIndex:j]) {
break;
}
else if(j == k-1){
[arrNew addObject:[arr objectAtIndex:i]];
}
}
}
}
NSLog(#"%#",[arrNew description]);
You can use these methods, which are provided by NSArray/NSMutableArray:
In NSArray see section "Finding Objects in an Array" for filtering methods starting with "indexesOfObjects...", e.g. indexesOfObjectsPassingTest:
In NSArray see section "Deriving New Arrays" for the method filteredArrayUsingPredicate:
In NSMutableArray there is a method filterUsingPredicate:
For narrowing the results you can continue applying the filtering consecutively to the filtered arrays or index sets.
Example with indexesOfObjectsPassingTest: using a block:
NSArray *strings = [NSArray arrayWithObjects:#"A", #"a", #"aB", #"AbC", #"Bag", #"Babc", #"baCK", #"", #"dba", nil];
NSString *searchString = #"Ab";
BOOL (^startsWithPredicate)(id, NSUInteger, BOOL*) = ^BOOL (id obj, NSUInteger idx, BOOL *stop) {
NSString *string = (NSString *) obj;
NSRange range = [string rangeOfString:searchString options:NSCaseInsensitiveSearch];
return (range.location == 0);
};
NSIndexSet *indexSet = [strings indexesOfObjectsPassingTest:startsWithPredicate];
NSLog(#"Strings found: %#", [strings objectsAtIndexes:indexSet]);
Output:
Strings found: (
aB,
AbC
)

How to get index value of search data in table view in iPhone

I am using a tableview controller with the searchbar. I want to get all index positions of the array elements which are related to a search result of any string from a table.
For example: If I have an array containing the following: #"sau",#"jain",#"abc",#"sau",#"zyx" and I search for 'sau' then I want it to output index 0 and 3.
How might I achieve this?
Try following code:
NSArray *array = #[ #"sau", #"jain", #"abc", #"sau", #"zyx" ];
NSString *searchString = #"sau";
NSIndexSet *result = [array indexesOfObjectsPassingTest:^BOOL(NSString *string, NSUInteger idx, BOOL *stop) {
NSRange searchStringRange = [string rangeOfString:searchString options:NSCaseInsensitiveSearch];
return searchStringRange.length > 0;
}];
NSLog(#"Result indexes: %#", result);
Console output is Result indexes: <NSIndexSet: 0x8a80c50>[number of indexes: 2 (in 2 ranges), indexes: (0 3)]
Tune code within the block to match you search logic
Edit
Or to process objects on one by one basis
NSArray *array = #[ #"sau", #"jain", #"abc", #"sau", #"zyx" ];
NSString *searchString = #"sau";
[array enumerateObjectsUsingBlock:^(NSString *obj, NSUInteger idx, BOOL *stop) {
BOOL searchCondition = [obj isEqualToString:searchString];
if (!searchCondition) return;
// You logic to process objects passing the search condition
}];

Search index of NSMutableArray

I need to search the index of a string from NSMutableArray. I have implemented the code & which works perfect, but I need to increase the searching speed than this.
I have used the following code:
NSIndexSet *indexes = [mArrayTableData indexesOfObjectsPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop){
NSString *s = (NSString*)obj;
NSRange range = [s rangeOfString: txtField.text options:NSCaseInsensitiveSearch];
if(range.location == 0)//
return range.location != NSNotFound;
return NO;
}];
NSLog(#"indexes.firstIndex =%d",indexes.firstIndex);
There is a method indexOfObject
NSString *yourString=#"Your string";
NSMutableArray *arrayOfStrings = [NSMutableArray arrayWithObjects: #"Another strings", #"Your string", #"My String", nil];
NSInteger index=[arrayOfStrings indexOfObject:yourString];
if(NSNotFound == index) {
NSLog(#"Not Found");
}
If you only want one index (or just the first one if there are multiples), you can use the singular version of the method you posted. You also don't need the if clause:
NSInteger index = [mArrayTableData indexOfObjectPassingTest:^BOOL(NSString *obj, NSUInteger idx, BOOL *stop){
return [obj.lowercaseString isEqualToString:txtField.text.lowercaseString];
}];
If you want to find strings that start with the search string, just replace isEqualToString: with hasPrefix:. With a large search set, this appears to be about twice as fast as the method you posted.

How to search in NSArray?

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.

How retrieve an index of an NSArray using a NSPredicate?

I would know how retrieve an index of an NSArray using a NSPredicate ?
NSArray *array = [NSArray arrayWithObjects:
#"New-York City",
#"Washington DC",
#"Los Angeles",
#"Detroit",
nil];
Which kind of method should I use in order to get the index of "Los Angles" by giving only a NSString?
NB: #"Los An" or #"geles" should return the same index.
Using NSPredicate you can get array of strings that contain your search string (it seems there's no built-in method to get just element indexes):
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF CONTAINS[cd] %#", searchString];
NSArray *filteredArray = [array filteredArrayUsingPredicate: predicate];
You can get only indexes using indexesOfObjectsPassingTest: method:
NSIndexSet *indexes = [array indexesOfObjectsPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop){
NSString *s = (NSString*)obj;
NSRange range = [s rangeOfString: searchString];
return range.location != NSNotFound;
}];
If you want to get just one element containing your string you can use similar indexOfObjectPassingTest: method for that.
You should be able to do this with blocks. Below is a snippet (I don't have a compiler handy so pls excuse any typos):
NSArray *array = [NSArray arrayWithObjects:
#"New-York City",
#"Washington DC",
#"Los Angeles",
#"Detroit",
nil];
NSString *matchCity = #"Los";
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF contains[cd] %#", matchCity];
NSUInteger index = [self.array indexOfObjectPassingTest:^(id obj, NSUInteger idx, BOOL *stop) {
return [predicate evaluateWithObject:obj];
}];
Essentially you can use the indexOfObjectPassingTest: method. This takes a block (code following the "^") and returns the index for the first object that matches your predicate (or NSNotFound if no match exists). The block iterates through each object in the array until either a match is found (at which point it returns the index) or no match is found (at which point it returns NSNotFound). Here is a link to block programming that can help you understand the logic within the block:
https://developer.apple.com/library/ios/featuredarticles/Short_Practical_Guide_Blocks/
Found an alternative approach helpful where the search is more complex as it allows predicate to be used to find object then object to find index:
-(NSIndexPath*) indexPathForSelectedCountry{
NSUInteger indexToCountry = 0;
NSPredicate * predicate = [NSPredicate predicateWithFormat:#"isoCode = %#",self.selectedCountry.isoCode];
NSArray * selectedObject = [self.countryList filteredArrayUsingPredicate:predicate];
if (selectedObject){
if (self.searchDisplayController.isActive){
indexToCountry = [self.searchResults indexOfObject:selectedObject[0]];
}else{
indexToCountry = [self.countryList indexOfObject:selectedObject[0]];
}
}
return [NSIndexPath indexPathForRow:indexToCountry inSection:0];
}
I would do this..
NSString * stringToCompare = #"geles";
int foundInIndex;
for ( int i=0; i<[array count]; i++ ){
NSString * tryString = [[array objectAtIndex:i] description];
if ([tryString rangeOfString:stringToCompare].location == NSNotFound) {
// no match
} else {
//match found
foundInIndex = i;
}
}// end for loop
Based on #Louie answer, instead of using for loop i had used enumeration block which worked for me.
I did this :-
NSString *stringToCompare = #"xyz";
[myArray enumerateObjectsUsingBlock:^(id *Obj, NSUInteger idx, BOOL * _Nonnull stop) {
NSString * tryString = [[myArray objectAtIndex:idx] description];
if ([tryString rangeOfString:stringToCompare].location == NSNotFound) {
// no match found
} else {
//match found and perform your operation. In my case i had removed array object at idx
}
}];