I am new to iphone.I have an array which contains the objects like below
"04_Num",
"04_Num/04Num.m3u",
"04_Num/04Num001.mp3",
"04_Num/04Num002.mp3",
"04_Num/04Num003.mp3",
"04_Num/04Num004.mp3",
"04_Num/04Num005.mp3",
"04_Num/04Num006.mp3",
"04_Num/04Num007.mp3",
"04_Num/04Num008.mp3",
"04_Num/04Num009.mp3",
"04_Num/04Num010.mp3",
"04_Num/04Num011.mp3",
"04_Num/04Num012.mp3",
"04_Num/04Num013.mp3",
"04_Num/04Num014.mp3",
"04_Num/04Num015.mp3",
"04_Num/04Num016.mp3",
"04_Num/04Num017.mp3",
"04_Num/04Num018.mp3",
"04_Num/04Num019.mp3",
"04_Num/04Num020.mp3",
"04_Num/04Num021.mp3",
"04_Num/04Num022.mp3",
"04_Num/04Num023.mp3",
"04_Num/04Num024.mp3",
"04_Num/04Num025.mp3",
"04_Num/04Num026.mp3",
"04_Num/04Num027.mp3",
"04_Num/04Num028.mp3",
"04_Num/04Num029.mp3",
"04_Num/04Num030.mp3",
"04_Num/04Num031.mp3",
"04_Num/04Num032.mp3",
"04_Num/04Num033.mp3",
"04_Num/04Num034.mp3",
"04_Num/04Num035.mp3",
"04_Num/04Num036.mp3"
but here i want the objects only which contains .mp3 extension and then i have to place those objects into another array
how it is possible if any body know this please help me...
You can iterate and get only the one that has .mp3
Like so
//yourArrayThatContainsAllStrings contains all the strings
NSMutableArray *arrayOfMp3 = [[NSMutableArray alloc] init];
for (NSString *str in yourArrayThatContainsAllStrings) {
if ([str rangeOfString:#".mp3"].location != NSNotFound) {
[arrayOfMp3 addObject:str];
}
}
//arrayOfMp3 will contain only the .mp3 files
NSMutableArray *mpthrees = [[NSMutableArray alloc] initWithCapacity:0];
for (NSString *file in songs) //Where songs is the array with the paths you have provided
{
BOOL isMpthree = [[file pathExtension] isEqualToString:#"mp3"];
if (isMpthree) [mpthrees addObject:file];
}
// Now mpthrees array holds only paths pointing to .mp3 files
// Let's call your array of strings as stringsArray
NSMutableArray *filteredArray = [[NSMutableArray alloc] init];
for (NSString *str in stringsArray) {
if ([str hasSuffix:#".mp3"]) {
[filteredArray addObject:str];
} }
//filteredArray will contain only the strings ending with ".mp3"
P.S. Since you're just beginning Objective C, i would like to reiterate that Objective C NSString objects always start with an # symbol. #"04_Num/04Num001.mp3"
Related
I am new to iphone.I have an array which contains the objects like below
"04_Num/04Num001.mp3",
"04_Num/04Num002.mp3",
"04_Num/04Num003.mp3",
"04_Num/04Num004.mp3",
"04_Num/04Num005.mp3",
"04_Num/04Num006.mp3",
"04_Num/04Num007.mp3",
"04_Num/04Num008.mp3",
"04_Num/04Num009.mp3",
"04_Num/04Num010.mp3",
"04_Num/04Num011.mp3",
"04_Num/04Num012.mp3",
"04_Num/04Num013.mp3",
"04_Num/04Num014.mp3",
"04_Num/04Num015.mp3",
"04_Num/04Num016.mp3",
"04_Num/04Num017.mp3",
"04_Num/04Num018.mp3",
"04_Num/04Num019.mp3",
"04_Num/04Num020.mp3",
"04_Num/04Num021.mp3",
"04_Num/04Num022.mp3",
"04_Num/04Num023.mp3",
"04_Num/04Num024.mp3",
"04_Num/04Num025.mp3",
"04_Num/04Num026.mp3",
"04_Num/04Num027.mp3",
"04_Num/04Num028.mp3",
"04_Num/04Num029.mp3",
"04_Num/04Num030.mp3",
"04_Num/04Num031.mp3",
"04_Num/04Num032.mp3",
"04_Num/04Num033.mp3",
"04_Num/04Num034.mp3",
"04_Num/04Num035.mp3",
"04_Num/04Num036.mp3"
but here i want retrieve the strings(objects)only after the / (i.e) for example 04_Num/04Num033.mp3 in this i want only the string 04Num033.mp3.Like this for all the above and then i have to place in an array
how it is possible if any body know this please help me...
lastPathComponent is what you need. You could do it like so:
NSMutableArray *files = [[NSMutableArray alloc] initWithCapacity:0];
for (NSString *file in songs) //Where songs is the array with the paths you have provided
{
[files addObject:[file lastPathComponent]];
}
You can separate the string into two parts using NSString's
componentsSeparatedByString:
method, and use the last string component
// Let's call your array of strings as stringsArray
NSMutableArray *prefixStrings = [[NSMutableArray alloc] init];
for (NSString *str in stringsArray) {
NSArray *stringComponents = [str componentsSeparatedByString:#"/"];
if ([stringComponents count]) {
[prefixStrings addObject:[stringComponents objectAtIndex:1]];
} }
The title pretty much says it all, but just to clarify: I have an NSMutableDictonary containing several NSMutableArrays. What I would like to do is find any value that is present in multiple arrays (there will not be any duplicates in a single array) and return that value. Can someone please help? Thanks in advance!
Edit: For clarity's sake I will specify some of my variables:
linesMutableDictionary contains a list of Line objects (which are a custom NSObject subclass of mine)
pointsArray is an array inside each Line object and contains the values I am trying to search through.
Basically I am trying to find out which lines share common points (the purpose of my app is geometry based)
- (NSValue*)checkForDupes:(NSMutableDictionary*)dict {
NSMutableArray *derp = [NSMutableArray array];
for (NSString *key in [dict allKeys]) {
Line *temp = (Line*)[dict objectForKey:key];
for (NSValue *val in [temp pointsArray]) {
if ([derp containsObject:val])
return val;
}
[derp addObjectsFromArray:[temp pointsArray]];
}
return nil;
}
this should work
If by duplicates you mean returning YES to isEqual: you could first make an NSSet of all the elements (NSSet cannot, by definition, have duplicates):
NSMutableSet* allElements = [[NSMutableSet alloc] init];
for (NSArray* array in [dictionary allValues]) {
[allElements addObjectsFromArray:array];
}
Now you loop through the elements and check if they are in multiple arrays
NSMutableSet* allDuplicateElements = [[NSMutableSet alloc] init];
for (NSObject* element in allElements) {
NSUInteger count = 0;
for (NSArray* array in [dictionary allValues]) {
if ([array containsObject:element]) count++;
if (count > 1) {
[allDuplicateElements addObject:element];
break;
}
}
}
Then you have your duplicate elements and don't forget to release allElements and allDuplicateElements.
I am trying to use plist files to save a list of items from a text
file from a web site. When I first create the plist file and add
items to that, there is no problem. But when I try to remove an item
from plist, it is not removing the index, it only overwrites the
content of this index with NULL. And I tried an other way; I tried to
create a new array without the item I want to remove, and overwrite
plist file with the content of this new array. In this way, the item
I wanted to remove is removed, but surprisingly the first item gets
NULL! A more surprising situation is, I also write it to a new plist
file with same technique, and it is perferct! This is a very
primitive code, unfortunately it didn't worked for me. I searched
plenty of tutorials, but I couldn't overcome. How can I write the
content of a string array to a plist file without extra null objects
and without loosing datas?
========================================================================
I composed a sample code below :
- (IBAction)logFromPlist{
NSMutableArray *arr = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"]];
NSLog(#"LOG:");
NSLog(#"arrplist count : %d", [arr count]);
for(int a=0; a<[arr count]; a++){
NSLog(#"*** %#", [arr objectAtIndex:a]);
}
}
- (IBAction)logFromPlist2{
NSMutableArray *arr = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data3.plist"]];
NSLog(#"LOG:");
NSLog(#"arrplist count : %d", [arr count]);
for(int a=0; a<[arr count]; a++){
NSLog(#"*** %#", [arr objectAtIndex:a]);
}
}
- (IBAction)addValue{
NSString *deger = [field5 text]; //New value text field in IB
NSMutableArray *arr = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"]];
if(arr == NULL){
arr = [[NSMutableArray alloc] init];
}
[arr addObject:deger];
[arr writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] atomically:NO];
}
- (IBAction)removeFromPlist{
NSMutableArray *arr2 = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"]];
if(arr2 != NULL){
NSMutableArray *arr = [[NSMutableArray alloc] init];
NSString *key = [field8 text];
for(int i = 0; i < [arr2 count]; i++){
NSString *cntStr = [[NSNumber numberWithInt:i] stringValue];
if(![cntStr isEqualToString:key]){
NSString *tempDeger = [arr2 objectAtIndex:i];
if(tempDeger != NULL){
[arr addObject:tempDeger];
}else{
NSLog(#"it is NULL");
}
}
}
NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager removeItemAtPath:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] error:nil]; //I tried this line by removing next line
[arr writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] atomically:NO]; //It is writing the array to plist but first item is always null
[arr writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data3.plist"] atomically:NO]; //same technique but everything is ok in this plist
[fileManager copyItemAtPath:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data3.plist"] toPath:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] error:nil]; // trying to copy correct plist file (data3.plist) to original plist file (plist2), but it does not fix the problem.
}
}
Project file : http://www.ozgunbursalioglu.com/files/plistWork.zip
At least your copyItemAtPath: will always fail since it won't overwrite files (data2.plist already exists).
Try to write your file by setting the automatically to YES
[arr writeToFile:PATH atomically:YES];
And also try to check the BOOL value returned to see if your oerration done successfully
I'm developing for iOS 5, say I have 2 arrays, the second only contains items contained on the first one.
I want to remove this object in every array it's present.
So, is there a way to easily remove an object from all arrays that contains it?
NSMutableArray *totalArray = [ [ NSMutableArray alloc] init];
//here i assume u want to delete NSString object vijay in all arrays
NSString *toDelete=#"vijay";
[totalArray addObject:firstArray];
[totalArray addObject:secondArray];
for (NSMutableArray *arr in totalArray) {
if ([arr containsObject:toDelete]) {
[arr removeObject:toDelete];
}
}
NSLog(#"firstarry : %# \n\n",firstArray);
NSLog(#"secondarray : %# \n\n",secondArray);
I want to parse a JSON file in my iphone app. The problem is i can parse simple json files but i am confused how to do parsing on following type of json:
[{"123":
[{ "item_id":"222",
"image_count":"2",
"image_filetype":".jpg",
"image_url":"http:\/\/someurl.jpg",
},
{"item_id":"333",
"image_count":"2",
"image_filetype":".jpg",
"image_url":"http:\/\/someurl.jpg",
}]
}]
Can some on help me how to extract all the img_urls for "123".
Thank you.
NSString *jsonString = …;
// The top-level object is an array
NSArray *array = [jsonString JSONValue];
// The first element in the array is an object containing a name-value
// pair for the key/name "123". The value is itself an array
NSArray *itemsIn123 = [[array objectAtIndex:0] objectForKey:#"123"];
// Use Key-Value Coding to get an array of all values for the key
// image_url
NSArray *imgurls = [itemsIn123 valueForKey:#"image_url"];
Edit based on comments:
Since the top-level array may consist of several objects, each object having a single name-value pair with unknown name, you need to manually iterate over the top-level array:
NSString *jsonString = …;
NSMutableArray *imgurls = [NSMutableArray array];
// The top-level object is an array
NSArray *array = [jsonString JSONValue];
// Each element in the top-level array is an object
for (NSDictionary *outerObject in array) {
// Iterate over all values in the object. Each (single) value is an array
for (NSArray *innerArray in [outerObject allValues]) {
[imgurls addObjectsFromArray:[innerArray valueForKey:#"image_url"]];
}
}
The value for the object "123" will be an NSArray of NSDictionaries. Each of these dictionaries has a key "image_url" for the image url.
The code will depend on which JSON parsing library you use, but the basics should be the same.
First you want to take the key values like 123,112,189 so we will take the keys into an array
say the structure like [ Web { 123 {image url} 112 {image url} 189 {image url} ]
so
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
SBJSON *jsonParser = [SBJSON alloc]init];
NSMutableArray *yourArray1 = [jsonParser objectWithString:responseString]copy]]autorelease;
ufArray = [[yourArray1 valueForKey:#"web"] copy];
for (NSString *s in ufArray) {
[keys addObject:[NSDictionary dictionaryWithObjectsAndKeys:s,#"keys",nil]];
}
NSLOG(#"keys :%#",keys);
// this will contain 112,123,114 etc values
initialize a NSMutableArray
finalArray = [NSMutableArray alloc]init];
for (int i = 0; i < [ufArray count]; i ++) {
yourArray1 = [ufArray valueForKey:[[keys objectAtIndex:i]valueForKey:#"keys"]];
// [keys object at indes:i] - > 123 val / next loop 112 array like that
[finalArray addObject:yourArray1];
}
[jsonParser release];
jsonParser = nil;
Hope this helps!
Well if that array was called jArray
var img_urls = [];
var jL = jArray[0][123].length;
var img_urls = [];
for(var i = 0; i < jL; i++){
img_urls[i] = jArray[0][123][i].image_url;
}
//display in console:
console.log(img_urls);
demo: http://jsfiddle.net/maniator/Vx3hu/4/
I've never used JSON before, never used iPhone before, never used Xcode before...but I would think its something along along the lines of...
//object and image for item ID 222
123: item_id(222).image_url("some_url")
or the second and following items
//hi
123: item_id(333).image_url("some_url")
However something better would be when you can extract the image without the URL by using the item ID and an image ID, so when calling the object 123, you can specify the item id and the image id, which would then output all the information you require. For instance the count, file type and the image could all be displayed.
123: item_id(222).image_id(222)
Is the data file SQL or XML? XML is usually faster! So read up on nodes.
Hope that helps.
DL.