Split NSString and Limit the response - ios

I have a string Hello-World-Test, I want to split this string by the first dash only.
String 1:Hello
String 2:World-Test
What is the best way to do this? What I am doing right now is use componentsSeparatedByString, get the first object in the array and set it as String 1 then perform substring using the length of String 1 as the start index.
Thanks!

I added a category on NSString to split on the first occurrence of a given string. It may not be ideal to return the results in an array, but otherwise it seems fine. It just uses the NSString method rangeOfString:, which takes an NSString(B) and returns an NSRange showing where that string(B) is located.
#interface NSString (Split)
- (NSArray *)stringsBySplittingOnString:(NSString *)splitString;
#end
#implementation NSString (Split)
- (NSArray *)stringsBySplittingOnString:(NSString *)splitString
{
NSRange range = [self rangeOfString:splitString];
if (range.location == NSNotFound) {
return nil;
} else {
NSLog(#"%li",range.location);
NSLog(#"%li",range.length);
NSString *string1 = [self substringToIndex:range.location];
NSString *string2 = [self substringFromIndex:range.location+range.length];
NSLog(#"String1 = %#",string1);
NSLog(#"String2 = %#",string2);
return #[string1, string2];
}
}
#end

Use rangeOfString to find if split string exits and then use substringWithRange to create new string on bases of NSRange.
For Example :
NSString *strMain = #"Hello-World-Test";
NSRange match = [strMain rangeOfString:#"-"];
if(match.location != NSNotFound)
{
NSString *str1 = [strMain substringWithRange: NSMakeRange (0, match.location)];
NSLog(#"%#",str1);
NSString *str2 = [strMain substringWithRange: NSMakeRange (match.location+match.length,(strMain.length-match.location)-match.length)];
NSLog(#"%#",str2);
}

Related

Find substring range of NSString with unicode characters

If I have a string like this.
NSString *string = #"😀1😀3😀5😀7😀"
To get a substring like #"3😀5" you have to account for the fact the smiley face character take two bytes.
NSString *substring = [string substringWithRange:NSMakeRange(5, 4)];
Is there a way to get the same substring by using the actual character index so NSMakeRange(3, 3) in this case?
Thanks to #Joe's link I was able to create a solution that works.
This still seems like a lot of work for just trying to create a substring at unicode character ranges for an NSString. Please post if you have a simpler solution.
#implementation NSString (UTF)
- (NSString *)substringWithRangeOfComposedCharacterSequences:(NSRange)range
{
NSUInteger codeUnit = 0;
NSRange result;
NSUInteger start = range.location;
NSUInteger i = 0;
while(i <= start)
{
result = [self rangeOfComposedCharacterSequenceAtIndex:codeUnit];
codeUnit += result.length;
i++;
}
NSRange substringRange;
substringRange.location = result.location;
NSUInteger end = range.location + range.length;
while(i <= end)
{
result = [self rangeOfComposedCharacterSequenceAtIndex:codeUnit];
codeUnit += result.length;
i++;
}
substringRange.length = result.location - substringRange.location;
return [self substringWithRange:substringRange];
}
#end
Example:
NSString *string = #"😀1😀3😀5😀7😀";
NSString *result = [string substringWithRangeOfComposedCharacterSequences:NSMakeRange(3, 3)];
NSLog(#"%#", result); // 3😀5
Make a swift extension of NSString and use new swift String struct. Has a beautifull String.Index that uses glyphs for counting characters and range selecting. Very usefull is cases like yours with emojis envolved

In objective-c how to get characters after n-th?

I have a number which will be represented as string. It is longer than 4 chars. I need to create new string from 5th till the end for that number.
For example if I have 56789623, I need to have 9623 as a result (5678 | 9623).
How to do that?
P.S. I suppose that this is very simple question, but I don't know how properly ask Google about that.
NSString *str = #"56789623";
NSString *first, *second;
if ([str length] > 4) {
first = [str substringWithRange:NSMakeRange(0, 4)];
second = [str substringWithRange:NSMakeRange(4, [str length] - 4)];
} else {
first = str;
second = nil;
}
Use this Simple functions
- (NSString *)substringFromIndex:(NSUInteger)from;
- (NSString *)substringToIndex:(NSUInteger)to;
- (NSString *)substringWithRange:(NSRange)range;
You can use:
- (NSString *)substringFromIndex:(NSUInteger)anIndex
NSString *number = #"56789623";
NSString *result = [number substringFromIndex:4];
NSLog(#"%#", result);
result contains the string: #"9623"
The keywords you were looking for are: substring and range. There are several ways to use them. Example code split string into 2 equal (if number of characters is even almost equal) substrings:
NSString *str = #"56789623";
NSInteger middleIndex = (NSInteger)(str.length/2);
NSString *strFirstPart = [str substringToIndex:middleIndex];
NSString *strSecondPart = [str substringFromIndex:middleIndex];
NSString *strFirstPart2 = [str substringWithRange:NSMakeRange(0, middleIndex)];
NSString *strSecondPart2 = [str substringWithRange:NSMakeRange(middleIndex, [str length]-middleIndex)];

Replace String Between Two Strings

I have a serious problem about indexing in array. I've been working on this for 2 days and couldn't find answer yet.
I want to do that, search specific character in array then replace it with other string. I'm using replaceObjectAtIndex method but my code is doesn't work.
Here is my code;
NSString *commentText = commentTextView.text;
NSUInteger textLength = [commentText length];
NSString *atSign = #"#";
NSMutableArray *commentArray = [[NSMutableArray alloc] init];
[commentArray addObject:commentText];
for (int arrayCounter=1; arrayCounter<=textLength; arrayCounter++)
{
NSRange isRange = [commentText rangeOfString:atSign options:NSCaseInsensitiveSearch];
if(isRange.location != NSNotFound)
{
commentText = [commentText stringByReplacingOccurrencesOfString:commentText withString:atSign];
[_mentionsearch filtrele:_mentionText];
id<textSearchProtocol> delegate;
[delegate closeList:[[self.searchResult valueForKey:#"user_name"] objectAtIndex:indexPath.row]];
}
}
Ok, now i can find "#" sign in the text and i can match it. But this is the source of problem that, i can not replace any string with "#" sign. Here is the last part of code;
-(void)closeList
{
NSArray *arrayWithSign = [commentTextView.text componentsSeparatedByString:#" "];
NSMutableArray *arrayCopy = [arrayWithSign mutableCopy];
[arrayCopy replaceObjectAtIndex:isRange.location withObject:[NSString stringWithFormat:#"#%#",username]];
}
When im logging isRange.location value, it returns correct. But when im try to run, my application is crashing. So, i can not replacing [NSString stringWithFormat:#"#%#",username] parameter. How can i solve this problem?
If I understand correctly you want to change a substring in a string with a new string. In this case, why don't you use directly the stringByReplacingOccurrencesOfString method of NSString:
NSString *stringToBeChanged = #"...";
NSString *stringToBeChangedWith = #"...";
NSString *commentTextNew = [commentText stringByReplacingOccurrencesOfString:stringToBeChanged withString:stringToBeChangedWith];

NSSet to string separaing by comma

I have the next code for converting NSSet to string separating by comma:
-(NSString *)toStringSeparatingByComma
{
NSMutableString *resultString = [NSMutableString new];
NSEnumerator *enumerator = [self objectEnumerator];
NSString* value;
while ((value = [enumerator nextObject])) {
[resultString appendFormat:[NSString stringWithFormat:#" %# ,",value]];//1
}
NSRange lastComma = [resultString rangeOfString:#"," options:NSBackwardsSearch];
if(lastComma.location != NSNotFound) {
resultString = [resultString stringByReplacingCharactersInRange:lastComma //2
withString: #""];
}
return resultString;
}
It seems that it works, but I get here two warnings:
1. format string is not a string literal (potentially insecure)
2. incompatible pointer types assigning to nsmutablestring from nsstring
How to rewrite it to avoid of warnings?
There is another way to achieve what you are trying to do with fewer lines of code:
You can get an array of NSSet objects using:
NSArray *myArray = [mySet allObjects];
You can convert the array to a string:
NSString *myStr = [myArray componentsJoinedByString:#","];
stringByReplacingCharactersInRange method's return type NSString. You are assigning it to NSMutableString. Use mutable copy.
resultString = [[resultString stringByReplacingCharactersInRange:lastComma //2
withString: #""]mutablecopy]

Pull first name and last initial from string

I have an NSString that contains a users full name. Some names are in the standard first and last formation (Kyle Begeman) and others are just a single name (TechCrunch).
How would I grab the first name as is and then the first initial of the last name, and if there is only one name, just grab the whole name?
Basically I want the above to be turned into Kyle B. or just TechCrunch depending on the name.
NSString *username = #"Kyle Begeman"
NSString *otherUserName = #"TechCrunch"
converted to
#"Kyle B"
// No conversion because it is a single word name
#"TechCrunch"
Using substringToIndex is how I can grab the first letter in the whole string, and I know there is a way to separate the string by #" " whitespace into an array but I can figure out how to easily produce the result the way it needs to be.
Any help would be great!
(NSString*)firstNameWithInitial:(NSString*)userName {
NSArray *array = [userName componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
array = [array filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"SELF != ''"]];
NSString *firstName = [array objectAtIndex:0];
NSString finalNameString;
if ([array count] > 1) {
NSString *lastNameInitial = [[array objectAtIndex:1] substringToIndex:1];
finalNameString = [firstName stringByAppendingString:[NSString stringWithFormat:#" %#", lastNameInitial]];
else {
finalNameString = firstName;
}
return finalNameString;
}
This function should return what you need. Note that you can modify this to work with people who have more than 2 names, by checking the number of objects in the array.
Find a position pos of the first space in the string. If there is no space, or if the space is the last character of the string, then return the entire string; otherwise, return substring in the range from zero to pos+1, inclusive:
NSRange range = [str rangeOfString:#" "];
if (range.location == NSNotFound || range.location == str.length-1) {
return str;
} else {
return [str substringToIndex:range.location+1];
}
You could use NSScanner to find substrings.
NSString *name = #"Some name";
NSString *firstName;
NSString *lastName;
NSScanner *scanner = [NSScanner scannerWithString:name];
[scanner scanUpToString:#" " intoString:&firstName]; // Scan all characters up to the first space
[scanner scanUpToString:#"" intoString:&lastName]; // Scan remaining characters
if (lastName != nil) {
// It was no space and lastName is empty
} else {
// There was at least one space and lastName contains a string
}

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