I have a TextField which has values as shown below.
#"Testing<Car>Testing<Car2>Working<Car3 /Car 4> on the code"
Here I have to loop through the text field and check for the text present within Angle brackets(< >).
There can be space or any special characters within the Angle Brackets.
I tried using NSPredicate and also componentsSeparatedByString, but I was not able to get the exact text within.
Is there any way to get the exact text along with Angle Brackets. Like in the above mentioned example want only
#"<Car>,<Car2> , <Car3 /Car 4>"
Thanks for the help in Advance.
A possible solution is Regular Expression. The pattern checks for < followed by one or more non-> characters and one >.
enumerateMatchesInString extracts the substrings and append them to an array. Finally the array is flattened to a single string.
NSString *string = #"Testing<Car>Testing<Car2>Working<Car3 /Car 4> on the code";
NSRegularExpression *regex = [[NSRegularExpression alloc] initWithPattern:#"<[^>]+>" options:0 error:nil];
__block NSMutableArray<NSString *> *matches = [NSMutableArray array];
[regex enumerateMatchesInString:string options:0 range:NSMakeRange(0, string.length) usingBlock:^(NSTextCheckingResult * _Nullable result, NSMatchingFlags flags, BOOL * _Nonnull stop) {
if (result) [matches addObject:[string substringWithRange:result.range]];
}];
NSLog(#"%#", [matches componentsJoinedByString:#", "]);
We can solve it in different ways. Now I am showing one of the way. You can place textFiled.text in place of str.
NSString *str = #"This is just Added < For testing %# ___ & >";
NSRange r1 = [str rangeOfString:#"<" options: NSBackwardsSearch];
NSRange r2 = [str rangeOfString:#">" options: NSBackwardsSearch];
NSRange rSub = NSMakeRange(r1.location + r1.length, r2.location - r1.location - r1.length);
NSString *sub = [str substringWithRange:rSub];
Related
Given an NSString containing a sentence I would like to determine the number of gaps between the words.
I could use something like [[theString componentsSeparatedByString:#" "].
But that would only work if each gap is a single space character, there could be multiple.
You can use NSRegularExpression, like:
NSString *test = #"The quick brown fox jumped over the lazy dog";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"\\s+" options:0 error:NULL];
NSUInteger num = [regex numberOfMatchesInString:test options:0 range:NSMakeRange(0, test.length)];
NSLog(#"num: %lu", num);
The regular expression "\s+" matches one or more whitespace characters (it's written here with an extra "\" because we need a literal backslash in the NSString). numberOfMatchesInString:options:range: counts each run of one or more whitespace characters as a match, which is exactly what you want.
You can do it via componentsSeparatedByString - if you filter afterwards to ignore the empty strings:
NSString *theString = #"HI this is a test";
NSArray *arr = [theString componentsSeparatedByString:#" "];
arr = [arr filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *b) {
return [(NSString*)evaluatedObject length] > 0;
}]];
NSLog(#"number of words: %lu", arr.count);
NSLog(#"number of gaps: %lu", arr.count - 1);
Regex is the 'coolest' way, but this might be the fastest and cleanest
NSArray *components= [theString componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSLog(#"gaps: %f", components.count - 1);
I need to get the word that comes after a certain sign, and remove it.
example :
NSString *me=#" i am going to make !somthing great" ;
I need to remove the word something, together with the ! sign, where ever it will occur in that text.
Is there some method like stringByReplacingOccurrencesOfString: to not only find the sign ,but identify the word that attached to it ?
Thanks.
You want a regular expression. In this case, you want one with the pattern #"!\w*". (An NSScanner would also work, but I think a regular expression is more concise in this case.)
If you have reasons not to use regular expressions (or if you are not familiar with them) you can use following
NSString *me=#" i am going to make !somthing great" ;
NSRange r1 = [me rangeOfString:#"!"];
if (r1.location != NSNotFound) {
NSRange r2 = [me rangeOfCharacterFromSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]
options:0
range:NSMakeRange(r1.location, me.length - r1.location)];
if (r2.location != NSNotFound) {
me = [me stringByReplacingCharactersInRange:NSMakeRange(r1.location, r2.location - r1.location) withString:#""];
}
}
Here's code:
NSMutableString *mutableMe = [me mutableCopy];
NSError *error;
NSRegularExpression *regex = [[NSRegularExpression alloc] initWithPattern:#"!\\w*" options:0 error:&error];
[regex replaceMatchesInString:mutableMe options:0 range:NSMakeRange(0, [mutableMe length]) withTemplate:#""];
If you want to find it first than use
[regex enumerateMatchesInString:mutableMe options:0 range:NSMakeRange(0, [mutableMe length]) usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
NSRange rangeOfString = [result rangeAtIndex:0];
[mutableMe replaceCharactersInRange:rangeOfString withString:#""];
}];
Try following syntax this can help you
NSString *replacedString=[NSString stringByReplacingOccurancesOfString:#"!something" withString:#" "];
I want to split NSString into array with fixed-length parts. How can i do this?
I searched about it, but i only find componentSeparatedByString method, but nothing more. It's also can be done manually, but is there a faster way to do this ?
Depends what you mean by "faster" - if it is processor performance you refer to, I'd guess that it is hard to beat substringWithRange:, but for robust, easy coding of a problem like this, regular expressions can actually come in quite handy.
Here's one that can be used to divide a string into 10-char chunks, allowing the last chunk to be of less than 10 chars:
NSString *pattern = #".{1,10}";
Unfortunately, the Cocoa implementation of the regex machinery is less elegant, but simple enough to use:
NSString *string = #"I want to split NSString into array with fixed-length parts. How can i do this?";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern: pattern options: 0 error: &error];
NSArray *matches = [regex matchesInString:string options:0 range:NSMakeRange(0, [string length])];
NSMutableArray *result = [NSMutableArray array];
for (NSTextCheckingResult *match in matches) {
[result addObject: [string substringWithRange: match.range]];
}
Break the string into a sequence of NSRanges and then try using NSString's substringWithRange: method.
You can split a string in different ways.
One way is to split by spaces(or any character):
NSString *string = #"Hello World Obj C is Awesome";
NSArray *words = [string componentsSeparatedByString:#" "];
You can also split at exact points in a string:
NSString *word = [string substringWithRange:NSMakeRange(startPoint, FIXED_LENGTH)];
Simply put it in a loop for a fixed length and save to Mutable Array:
NSMutableArray *words = [NSMutableArray array];
for (int i = 0; i < [string length]; i++) {
NSString *word = [string substringWithRange:NSMakeRange(i, FIXED_LENGTH)]; //you may want to make #define
[array addObject:word];
}
Hope this helps.
My string looks something like this:
R392P328N87R3928N32P328N123
Line end is defined by that N followed by a number.
I need to split each line into an array object. I was thinking about using simply componentsSeparatedByString: but there's a number following N and I want it to include N in the created objects.
Also notice that what comes before N is not a constant.
In other words, from that line above, I need it to create 3 array objects:
R392P328N87
R3928N32
P328N123
What's the best way to go about doing this? Should I try something that looks for 'N' and stop when it reaches another non-hex letter(I might have hexadecimal after N)?
Thanks!
Elijah
Sounds like a job for regular expressions.
NSString *string = #"R392P328N87R3928N32P328N123";
NSString *pattern = #".*?N\\d+";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:NULL];
NSMutableArray *lines = [NSMutableArray array];
[regex enumerateMatchesInString:string options:0 range:NSMakeRange(0, string.length) usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
[lines addObject:[string substringWithRange:result.range]];
}];
NSLog(#"%#", lines);
// => ["R392P328N87", "R3928N32", "P328N123"]
what is the best way to get and replace specific words in string ?
for example I have
NSString * currentString = #"one {two}, thing {thing} good";
now I need find each {currentWord}
and apply function for it
[self replaceWord:currentWord]
then replace currentWord with result from function
-(NSString*)replaceWord:(NSString*)currentWord;
The following example shows how you can use NSRegularExpression and enumerateMatchesInString to accomplish the task. I have just used uppercaseString as function that replaces a word, but you can use your replaceWord method as well:
EDIT: The first version of my answer did not work correctly if the replaced words are
shorter or longer as the original words (thanks to Fabian Kreiser for noting that!) .
Now it should work correctly in all cases.
NSString *currentString = #"one {two}, thing {thing} good";
// Regular expression to find "word characters" enclosed by {...}:
NSRegularExpression *regex;
regex = [NSRegularExpression regularExpressionWithPattern:#"\\{(\\w+)\\}"
options:0
error:NULL];
NSMutableString *modifiedString = [currentString mutableCopy];
__block int offset = 0;
[regex enumerateMatchesInString:currentString
options:0
range:NSMakeRange(0, [currentString length])
usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
// range = location of the regex capture group "(\\w+)" in currentString:
NSRange range = [result rangeAtIndex:1];
// Adjust location for modifiedString:
range.location += offset;
// Get old word:
NSString *oldWord = [modifiedString substringWithRange:range];
// Compute new word:
// In your case, that would be
// NSString *newWord = [self replaceWord:oldWord];
NSString *newWord = [NSString stringWithFormat:#"--- %# ---", [oldWord uppercaseString] ];
// Replace new word in modifiedString:
[modifiedString replaceCharactersInRange:range withString:newWord];
// Update offset:
offset += [newWord length] - [oldWord length];
}
];
NSLog(#"%#", modifiedString);
Output:
one {--- TWO ---}, thing {--- THING ---} good