I need to input x and y co-ordinates into a custom object, the input is with the format "x,y"
I am currently storing the input as an NSString and need to get the integers out of it and into separate NSNumbers. If there is another way to store the input that would be easier, please explain.
I need to store x and y as separate NSNumbers, this also this needs to account for if x and y are 2 digits. i.e. "23,4"
can anyone help?
Use -[NSString componentsSeparatedByString:]
NSArray *numericComponents = [string componentsSeparatedByString:#","];
NSArray *numbers = [numericComponents map:^id(NSString *object) {
return #([object integerValue]);
}];
map here is simply a category method that I've added to NSArray:
#implementation NSArray (JRAdditions)
- (NSArray *)map:(id(^)(id))block {
if([self count] == 0 || block == nil) return self;
NSMutableArray *mapped = [NSMutableArray new];
NSArray *copy = [self copy];
for(id obj in copy) {
id mappedObject = block(obj);
if(mappedObject) {
[mapped addObject:mappedObject];
}
}
return [mapped copy];
}
#end
NSString *str=#"23,4";
NSArray *array=[str componentsSeparatedByString:#","];
NSNumber *xNum=#([array[0] integerValue]);
NSNumber *yNum=#([array[1] integerValue]);
To check if they are two digits :
if ([xNum integerValue]>9 && [xNum integerValue]<100) {
NSLog(#"x is 2 digits");
}
else{
}
if([yNum integerValue]>9 && [yNum integerValue]<100) {
NSLog(#"y is 2 digits");
}
else{
}
Related
Trying to create a method with only one parameter that may accept NSString or int.
Here's what I did so far:
-(NSString*)LocalizeNumber:(void*)TheNumber{
BOOL IsVarInt = false;
NSString * Num = "";
if(IsVarInt){
Num = [NSString stringWithFormat:#"%i",(int)TheNumber];
}else{
Num = [NSString stringWithFormat:#"%#",(__bridge NSString*)TheNumber];
}
//rest of code...
}
And this is how I call this method:
if passing int:
[self LocalizeNumber:(void*)150];
if passing NSString:
[self LocalizeNumber:#"150"];
The problem is that I still don't know how to know if the parameter "TheNumber" is NSString or int.
Thank you.
While I suggest you rethink your approach, your goal can be achieved as follows:
- (NSString *)localizeNumber:(id)number {
NSString *num = nil;
if ([number isKindOfClass:[NSNumber class]]) {
num = [number stringValue];
} else if ([number isKindOfClass:[NSString class]]) {
num = number;
} else {
// oops - bad value
}
// rest of code using num
}
Then you can call the method as follows:
NSString *someString = #"Hello";
NSString *result = [self localizeNumber:someString];
or:
int someInt = 42;
NSString *result = [self localizeNumber:#(someInt)];
You cannot tell between an object type and a plain primitive. However, you can easily tell between two object types if you pass an int passed in NSNumber wrapper, like this:
-(NSString*)LocalizeNumber:(id)TheNumber {
NSString *Num = #"";
if ([TheNumber isKindOfClass:[NSSTRING class]]) {
Num = [NSString stringWithFormat:#"%#", TheNumber];
} else if ([TheNumber isKindOfClass:[NSNumber class]]) {
Num = [NSString stringWithFormat:#"%i",[TheNumber intValue]];
}
//rest of code...
}
You could use categories to add -stringValue to NSString:
#implementation NSString (LocalizedNumber)
-(NSString*)stringValue
{
return self ;
}
#end
Then you can call:
NSString * localizedNumber = [<number or string object> stringValue]
There is no safe way to tell an int from an NSString reference.
I am generating a random equation say like 2*3+4..... and using DDMathparser to evaluate it. Here I have a class method which is supposed to return a random equation(stored inside a mutable array) only if it evaluates to a integer.
however it keeps returning Null and i can't figure out why. Please help me out.!
#import "Equation.h"
#import "DDMathParser.h"
#implementation Equation
-(NSMutableArray*)randEquation{
NSMutableArray* usableEquation=[[NSMutableArray alloc]init];
while(1){
NSArray *nums = #[#"1", #"2", #"3", #"4", #"5",#"6",#"7",#"8",#"9"];
unsigned index1=arc4random()%9;
NSString* num = [NSString stringWithFormat:#"%#", [nums objectAtIndex:index1]];
NSArray *symbols = #[#"+", #"-", #"*", #"/"];
unsigned index=arc4random()%4;
NSString* symb = [NSString stringWithFormat:#"%#", [symbols objectAtIndex:index]];
NSMutableArray *arrayOfSymbolsAndNumbers = [[NSMutableArray alloc] init];
for( int i=0;i<=10;i++){
if (i%2==0) {
[arrayOfSymbolsAndNumbers addObject:num];
}
else{
[arrayOfSymbolsAndNumbers addObject:symb];
}
}
NSMutableString *stringOfSymbolsAndNumbers=[[NSMutableString alloc]init];
for (NSObject * obj in arrayOfSymbolsAndNumbers)
{
[stringOfSymbolsAndNumbers appendString:[obj description]];
}
usableEquation=arrayOfSymbolsAndNumbers;
NSNumber *result=[stringOfSymbolsAndNumbers numberByEvaluatingString];
float resultFloat = [result floatValue];
float checker=resultFloat;
if (floor(checker)==checker) {
break;
}
else{
continue;
}
}
return usableEquation;
}
#end
NSLog(#"The content of array is%#",[equation randEquation]);
Based on your code, for this log to output The content of array is(null) means that equation is nil. Your randEquation (while not efficient) looks ok, the problem is that you haven't created the equation instance when you run the log statement.
I have filled a NSMutableArray with integer and string values from my database.
The problem is that many values were inserted more than once.
Using the following code I remove duplicate objects
for (id object in originalArray) {
if (![singleArray containsObject:object]) {
[singleArray addObject:object];
}
}
Bus this works only if the objects are exactly the same between them.
Is there a way to remove duplicates based on the integer value?
EDIT (from an OP's comment on a deleted answer)
I have some objects containing int and NSString. For example #"John 13", #"Mary 25", #"Luke 25", #"Joan 13". The NSMutableArray will contain all four names and duplicates of 13, 25. I want to remove the duplicates leaving 13 and 25 only once in the array. I do not care which names will be removed. Care only for the integer values to use them later.
If your elements are all NSNumber objects:
for (int i=0;i<array.count;i++) {
for (int j=i+1;j<array.count;j++) {
if ([array[i] isEqualToNumber:array[j]]) {
[array removeObjectAtIndex:j--];
}
}
}
Or if all objects are either integer NSNumbers or NSStrings containing integer values:
for (int i=0;i<array.count;i++) {
for (int j=i+1;j<array.count;j++) {
if ([array[i] intValue] == [array[j] intValue]) {
[array removeObjectAtIndex:j--];
}
}
}
Try this:
// singleArray is initially empty
for (id object in originalArray)
{
BOOL contains= YES;
for( id single in singleArray)
{
if( [single integerValue]==[object integerValue] )
{
contains= NO;
break;
}
}
if(contains)
{
[singleArray addObject: object];
}
}
no test, tell me if it does not work. assuming objects in the array are string and format is "WORD NUMBER"
Boolean myEqual(const void *value1, const void *value2) {
NSString *str1 = (__bridge NSString *)(value1);
NSString *str2 = (__bridge NSString *)(value2);
NSArray *arr1 = [str1 componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSArray *arr2 = [str2 componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
return [[arr1 lastObject] isEqual:[arr2 lastObject]];
}
CFHashCode myHash(const void *value) {
NSString *str1 = (__bridge NSString *)(value);
NSArray *arr1 = [str1 componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
return [[arr1 lastObject] hash];
}
NSMutableArray *array = // your array;
CFSetCallBacks callBacks = kCFTypeSetCallBacks;
callBacks.equal = myEqual;
callBacks.hash = myHash;
CFMutableSetRef set = CFSetCreateMutable(NULL, [array count], &callBacks);
for (id obj in [array copy]) { // copy so can modify the original array
if (CFSetContainsValue(set, (__bridge const void *)(obj))) {
[array removeObject:obj];
} else {
CFSetAddValue(set, (__bridge const void *)(obj));
}
}
When I Build & Run my application, it will not generate anything. What I have generating are words and after it erases that word and continues until it exhausts all the words and then repopulates the list again. Here is the code:
#implementation randomnumbersViewController
#synthesize words;
#synthesize randomArray;
#synthesize array;
-(IBAction)generateNumber:(id)sender {
NSInteger randomize(id num1, id num2, void *context);
int rand = arc4random() %2;
if (rand)
return NSOrderedAscending;
else
return NSOrderedDescending;
}
- (void)resetRandomArray;
{
[randomArray setArray: array];
[randomArray sortUsingFunction:random context:NULL];
}
- (NSString*) getRandomWord; {
if ([randomArray count] ==0)
return nil;
NSString* result;
NSInteger randomIndex = [[randomArray lastObject] intValue];
[randomArray removeLastObject];
result = [words objectAtIndex:randomIndex];
return result;
}
- (void)buildRandomWordArray
{
NSInteger index;
NSError *theError;
NSString *path = [[NSBundle mainBundle] pathForResource:#"words" ofType:#"text"];
NSString *text = [NSString stringWithContentsOfFile: path
encoding: NSUTF8StringEncoding
error: &theError];
self.words = [text componentsSeparatedByString: #"\n"];
int arraySize = [words count];
self.array = [NSMutableArray arrayWithCapacity:arraySize];
//This code fills "array' with index values from 0 to the number of elements in the "words" array.
for (index = 0; index<arraySize; index++)
[array addObject: [NSNumber numberWithInt: index]];
[self resetRandomArray];
//for (index = 0; index<=arraySize; index++)
// NSLog(# "Random word: %#", [self getRandomWord]);
}
Also a .txt document must be included in the resources folder in for this to work and I do have it there, but nothing. Does anyone have any suggestions as to how I can actually get it to generate the words, or why it isn't working properly?
I don't get how sorting the array ascending or descending is going to shuffle the array, maybe because it doesn't. :) You should use the Fisher–Yates shuffle implemented here: What's the Best Way to Shuffle an NSMutableArray? Import that category, and just call shuffle on the mutable array.
How can I save the string that match from one NSArray with one index difference in NSMutableArray?
For example, there are three "apple", four "pineapple", six "banana", two "cocoa" and the rest of words dont have duplicate(s) in the nsarray, i would like to know if the nsarray has at least two same words. If yes, I would like to save "apple", "pineapple, "banana" and "cocoa" once in nsmutablearray. If there are other alike words, I would like to add them to namutablearray too.
My code (which still doesn't work properly);
NSArray *noWords = [[NSArray alloc] initWithArray:
[[NSString stringWithContentsOfFile:[[NSBundle mainBundle]
pathForResource:#"words" ofType:#"txt"]
encoding:NSUTF8StringEncoding error:NULL]
componentsSeparatedByString:#"\n"]];
NSUInteger scount = [noWords count];
int ii = 0;
NSString *stringline;
for (ii; ii < scount; ii++)
{
stringline = [noWords objectAtIndex:ii];
NSLog(#"stringline : %# ", stringline);
}
int i = 1;
NSString *line;
for (i ; i < 10; i++)
{
line = [noWords objectAtIndex:i];
NSLog (#"line : %# ", line);
NSMutableArray *douwords = [NSMutableArray array];
if ([stringline isEqualToString:line])
{
NSString *newword;
for (newword in douwords)
{
[douwords addObject:newword];
NSLog (#"detected! %# ", douwords);
}
}
}
Here's a solution using two sets:
- (NSArray *)getDuplicates:(NSArray *)words
{
NSMutableSet *dups = [NSMutableSet set],
*seen = [NSMutableSet set];
for (NSString *word in words) {
if ([seen containsObject:word]) {
[dups addObject:word];
}
[seen addObject:word];
}
return [dups allObjects];
}
Assuming NSSet uses hash tables behind the scenes (which I'm betting it does), this is going to be faster than the previously suggested O(n^2) solution.
Here's something off the top of my head:
NSMutableSet* duplicates = [NSMutableSet set];
NSArray* words = [NSArray arrayWithObjects:#"Apple", #"Apple", #"Orange", #"Apple", #"Orange", #"Pear", nil];
[words enumerateObjectsUsingBlock:^(NSString* str, NSUInteger idx, BOOL *stop) {
for (int i = idx + 1; i < words.count; i++) {
if ([str isEqualToString:[words objectAtIndex:i]]) {
[duplicates addObject:str];
break;
}
}
}];
NSLog(#"Dups: %#", [duplicates allObjects]); // Prints "Apple" and "Orange"
The use of an NSSet, as opposed to an NSArray, ensures strings are not added more than once. Obviously, there are optimizations that could be done, but it should be a good starting point.
I assume that you want to count appearances of words in your array and output those with a count of more than one. A basic and verbose way to do that would be:
// Make an array of words - some duplicates
NSArray *wordList = [[NSArray alloc] initWithObjects:
#"Apple", #"Banana", #"Pencil",
#"Steve Jobs", #"Kandahar",
#"Apple", #"Banana", #"Apple",
#"Pear", #"Pear", nil];
// Make an mutable dictionary - the key will be a word from the list
// and the value will be a number representing the number of times the
// word appears in the original array. It starts off empty.
NSMutableDictionary *wordCount = [[NSMutableDictionary alloc] init];
// In turn, take each word in the word list...
for (NSString *s in wordList) {
int count = 1;
// If the word is already in the dictionary
if([wordCount objectForKey:s]) {
// Increse the count by one
count = [[wordCount objectForKey:s] intValue] + 1;
}
// Save the word count in the dictionary
[wordCount setObject:[NSNumber numberWithInt:count] forKey:s];
}
// For each word...
for (NSString *s in [wordCount keysOfEntriesPassingTest:
^(id key, id obj, BOOL *stop) {
if ([obj intValue] > 1) return YES; else return NO;
}]) {
// print the word and the final count
NSLog(#"%2d %#", [[wordCount objectForKey:s] intValue], s);
}
The output would be:
3 Apple
2 Pear
2 Banana