How can I count the occurrence of a character in a string?
Example
String: 123-456-7890
I want to find the occurrence count of "-" in given string
You can simply do it like this:
NSString *string = #"123-456-7890";
int times = [[string componentsSeparatedByString:#"-"] count]-1;
NSLog(#"Counted times: %i", times);
Output:
Counted times: 2
This will do the work,
int numberOfOccurences = [[theString componentsSeparatedByString:#"-"] count];
I did this for you. try this.
unichar findC;
int count = 0;
NSString *strr = #"123-456-7890";
for (int i = 0; i<strr.length; i++) {
findC = [strr characterAtIndex:i];
if (findC == '-'){
count++;
}
}
NSLog(#"%d",count);
int total = 0;
NSString *str = #"123-456-7890";
for(int i=0; i<[str length];i++)
{
unichar c = [str characterAtIndex:i];
if (![[NSCharacterSet alphanumericCharacterSet] characterIsMember:c])
{
NSLog(#"%c",c);
total++;
}
}
NSLog(#"%d",total);
this worked. hope it helps. happy coding :)
int num = [[[myString mutableCopy] autorelease] replaceOccurrencesOfString:#"-" withString:#"X" options:NSLiteralSearch range:NSMakeRange(0, [myString length])];
The replaceOccurrencesOfString:withString:options:range: method returns the number of replacements that were made, so we can use that to work out how many -s are in your string.
You can use replaceOccurrencesOfString:withString:options:range: method of NSString
The current selected answer will fail if the string starts or ends with the character you are checking for.
Use this instead:
int numberOfOccurances = (int)yourString.length - (int)[yourString stringByReplacingOccurrencesOfString:#"-" withString:#""].length;
Related
i am trying to convert my hex value to binary value , but i am facing little problem .
as i am new trying to learn my faults .
my code :
NSMutableString *str;
NSString *dd = #"192:168:1:2:0B:2:D:00";
NSCharacterSet *donotwant1 = [NSCharacterSet characterSetWithCharactersInString:#":""];
dd =[[dd componentsSeparatedByCharactersInSet:donotwant1] componentsJoinedByString:#" "];
NSMutableArray *array = [[dd componentsSeparatedByString:#" "] mutableCopy];
[array removeObjectAtIndex:0];
//NSLog(#"%#",array);
for (int j=0; j<[array count]; j++) {
NSScanner *scan = [NSScanner scannerWithString:[array objectAtIndex:j]];
unsigned int i=0;
if ([scan scanHexInt:&i]) {
// NSLog(#"numbner is %ustr", i);
}
NSInteger theNumber = i;
str = [NSMutableString string];
for(NSInteger numberCopy = theNumber; numberCopy > 0; numberCopy >>= 1) {
// Prepend "0" or "1", depending on the bit
[str insertString:((numberCopy & 1) ? #"1" : #"0") atIndex:0];
[array removeObjectAtIndex:j];
[array insertObject:str atIndex:j];
}
}
NSLog(#"Binary version: %#", array);
I'm getting
1,1100,11001111,1111,1111,11101111.....
in my code 0 values are eliminated . i want 8bits like(00000001,00001100.....) can any one tell me the reason
When the most significant bit is reached, your algorithm stops the conversion. Why not force the loop to always execute 8 times?
for (int numberCopy = theNumber, int i = 0; i < 8; numberCopy >>= 1, i++) {
// loop body here
}
By the way, here's a cleaner/shorter/simpler approach that doesn't involve highly superfluous copying and uses characters instead of string objects for hyper efficiency (just kidding, I'm all against micro-optimizations, but I feel like inserting an NSString before another one is unnecessary, especially if the number of bits is known and constant). This also assumes UTF-8 and exploits the fact that hexadecimal and binary representation have a very nice relationship, 16 being the 4th power of 2:
NSString *dd = #"01:0C:CF:0F:EF:AF:BD:00";
NSArray *bytes = [dd componentsSeparatedByString:#":"];
NSMutableArray *binaries = [NSMutableArray array];
NSString *lookup[256];
lookup['0'] = #"0000";
lookup['1'] = #"0001";
lookup['2'] = #"0010";
lookup['3'] = #"0011";
lookup['4'] = #"0100";
lookup['5'] = #"0101";
lookup['6'] = #"0110";
lookup['7'] = #"0111";
lookup['8'] = #"1000";
lookup['9'] = #"1001";
lookup['A'] = #"1010";
lookup['B'] = #"1011";
lookup['C'] = #"1100";
lookup['D'] = #"1101";
lookup['E'] = #"1110";
lookup['F'] = #"1111";
for (NSString *s in bytes) {
unichar n1 = [s characterAtIndex:0];
unichar n0 = [s characterAtIndex:1];
[binaries addObject:[lookup[n1] stringByAppendingString:lookup[n0]]];
}
NSLog(#"%#", binaries);
my problem is pretty simple. I assign a value to string variable in xcode which looks like this:
ARAMAUBEBABRBGCNDKDEEEFO
and I need it like this:
AR,AM,AU,BE,BA,BR,BG,CN,DK,DE,EE,FO
The length is different in each variable.
thanx in advance
This function is usefull for numbers that need coma every thousands... which is what I wanted, hope it helps.
//add comas to a a string...
//example1: #"5123" = #"5,123"
//example2: #"123" = #"123"
//example3: #"123123123" = #"123,123,123"
-(NSString*) addComasToStringEvery3chrsFromRightToLeft:(NSString*) myString{
NSMutableString *stringFormatted = [NSMutableString stringWithFormat:#"%#",myString];
for(NSInteger i=[stringFormatted length]-3;i>0;i=i-3) {
if (i>0) {
[stringFormatted insertString: #"," atIndex: i];
}
}
return stringFormatted;
}
Try this:
int num;
NSMutableString *string1 = [NSMutableString stringWithString: #"1234567890"];
num = [string1 length];
for(int i=3;i<=num+1;i++) {
[string1 insertString: #"," atIndex: i];
i+=3;
}
NSString *yourString; // the string you want to process
int len = 2; // the length
NSMutableString *str = [NSMutableString string];
int i = 0;
for (; i < [yourString length]; i+=len) {
NSRange range = NSMakeRange(i, len);
[str appendString:[yourString substringWithRange:range]];
[str appendString:#","];
}
if (i < [str length]-1) { // add remain part
[str appendString:[yourString substringFromIndex:i]];
}
// str now is what your want
This would work well when your string is not very large:
NSString * StringByInsertingStringEveryNCharacters(NSString * const pString,
NSString * const pStringToInsert,
const size_t n) {
NSMutableString * const s = pString.mutableCopy;
for (NSUInteger pos = n, advance = n + pStringToInsert.length; pos < s.length; pos += advance) {
[s insertString:pStringToInsert atIndex:pos];
}
return s.copy;
}
If the string is very large, you should favor to compose it without insertion (append-only).
(define your own error detection)
Iam developing one applciation.In that i want to comapare the every character of string with other character.So please tell me how to do that one.
Use characterAtIndex: function of NSString to extract the character by index.
- (unichar)characterAtIndex:(NSUInteger)index
for (int i=0; i<[string length]; i++) {
char = [string characterAtIndex:i];
NSString *charString = [NSString stringWithFormat:#"%c", char];
if ([charString isEqualToString:comparisonString]) {
//match
}
else {
//no match
}
}
if you want to compare a string. Using isEqualToString method.
NSMutableString *str = [[NSMutableString alloc] initWithString:#"a"];
if([str isEqualToString:#"a"]){
// match
}
else{
// not match
}
I got a headache trying to count returns (\n) in my UITextView. As you'll soon realise, I'm a bloody beginner and here is my theory of what I've come up with, but there are many gaps...
- (IBAction)countReturns:(id)sender {
int returns;
while ((textView = getchar()) != endOfString [if there is such a thing?])
{
if (textView = getchar()) == '\n') {
returns++;
}
}
NSString *newText = [[NSString alloc] initWithFormat:#"Number of returns: %d", returns];
numberReturns.text = newText;
[newText release];
}
I checked other questions on here, but people are usually (in my eyes) lost in some details which I don't understand. Any help would be very much appreciated! Thanks for your patience.
You can simply
UITextView *theview; //remove this line, and change future theview to your veiw
NSString *thestring; //for storing a string from your view
int returnint = 0;
thestring = [NSString stringWithFormat:#"%#",[theview text]];
for (int temp = 0; temp < [thestring length]; temp++){ //run through the string
if ([thestring characterAtIndex: temp] == '\n')
returnint++;
}
NSArray *newlines = [textView.text componentsSeparatedByString:#"\n"];
int returns = ([newlines count]-1)
Should work. Keep in mind this isn't such a great idea if you have a gia-normous string, but it's quick, dirty and easy to implement.
there are a lot of ways to do that. Here is one:
NSString *str = #"FooBar\n\nBaz...\n\nABC\n";
NSString *tmpStr = [str stringByReplacingOccurrencesOfString:#"\n" withString:#""];
NSInteger count = [str length] - [tmpStr length];
NSLog(#"Count: %d", count);
i'm trying to build a function that will tell me the range of a string at an occurrence.
For example if I had the string "hello, hello, hello", I want to know the range of hello at it's, lets say, third occurrence.
I've tried building this simple function, but it doesn't work.
Note - the top functions were constructed at an earlier date and work fine.
Any help appreciated.
- (NSString *)stringByTrimmingString:(NSString *)stringToTrim toChar:(NSUInteger)toCharacterIndex {
if (toCharacterIndex > [stringToTrim length]) return #"";
NSString *devString = [[[NSString alloc] init] autorelease];
for (int i = 0; i <= toCharacterIndex; i++) {
devString = [NSString stringWithFormat:#"%#%#", devString, [NSString stringWithFormat:#"%c", [stringToTrim characterAtIndex:(i-1)]]];
}
return devString;
[devString release];
}
- (NSString *)stringByTrimmingString:(NSString *)stringToTrim fromChar:(NSUInteger)fromCharacterIndex {
if (fromCharacterIndex > [stringToTrim length]) return #"";
NSString *devString = [[[NSString alloc] init] autorelease];
for (int i = (fromCharacterIndex+1); i <= [stringToTrim length]; i++) {
devString = [NSString stringWithFormat:#"%#%#", devString, [NSString stringWithFormat:#"%c", [stringToTrim characterAtIndex:(i-1)]]];
}
return devString;
[devString release];
}
- (NSRange)rangeOfString:(NSString *)substring inString:(NSString *)string atOccurence:(int)occurence {
NSString *trimmedString = [inString copy]; //We start with the whole string.
NSUInteger len, loc, oldLength;
len = 0;
loc = 0;
NSRange tempRange = [string rangeOfString:substring];
len = tempRange.length;
loc = tempRange.location;
for (int i = 0; i != occurence; i++) {
NSUInteger endOfWord = len+loc;
trimmedString = [self stringByTrimmingString:trimmedString fromChar:endOfWord];
oldLength += [[self stringByTrimmingString:trimmedString toChar:endOfWord] length];
NSRange tmp = [trimmedString rangeOfString:substring];
len = tmp.length;
loc = tmp.location + oldLength;
}
NSRange returnRange = NSMakeRange(loc, len);
return returnRange;
}
Instead of trimming the string a bunch of times (slow), just use rangeOfString:options:range:, which searches only within the range passed as its third argument. See Apple's documentation.
So try:
- (NSRange)rangeOfString:(NSString *)substring
inString:(NSString *)string
atOccurence:(int)occurence
{
int currentOccurence = 0;
NSRange rangeToSearchWithin = NSMakeRange(0, string.length);
while (YES)
{
currentOccurence++;
NSRange searchResult = [string rangeOfString: substring
options: NULL
range: rangeToSearchWithin];
if (searchResult.location == NSNotFound)
{
return searchResult;
}
if (currentOccurence == occurence)
{
return searchResult;
}
int newLocationToStartAt = searchResult.location + searchResult.length;
rangeToSearchWithin = NSMakeRange(newLocationToStartAt, string.length - newLocationToStartAt);
}
}
You need to rework the whole code. While it may seem to work, it's poor coding and plain wrong, like permanently reassigning the same variable, initializing but reassigning one line later, releasing after returning (which will never work).
For your question: Just use rangeOfString:options:range:, and do this the appropriate number of times while just incrementing the starting point.