how to remove/truncate zero from left side of string - objective-c

i am trying to remove zero "0" from left in the string means if string is "0000560352"
it will give it to me "560352".
it's dynamically change so if user will enter in textbox like "0560352" then only first zero will remove from string.any idea for this thing.

It is too simple just convert it to NSInteger and then bring back to NSString
NSString *str = #"0000560352";
NSInteger i = [str integerValue];
str = [NSString stringWithFormat:#"%d",i];

You do not need a loop or a conversion
NSCharacterSet *zeros = [NSCharacterSet characterSetWithCharactersInString:#"0"];
NSString *nonLeadingZerosString = [#"000560352" stringByTrimmingCharactersInSet:zeros];
But at the end of the day you want to use a number formatter.

Related

Detect type from string objective-c

Whats the best way of detecting a data type from a string in Objective-c?
I'm importing CSV files but each value is just a string.
E.g. How do I tell that "2.0" is a number, "London" should be treated as a category and that "Monday 2nd June" or "2/6/2012" is a date.
I need to test the datatype some how and be confident about which type I use before passing the data downstream.
Regex is the only thing I can think about, but if you are on mac or iphone, than you might try e.g. RegexKitLite
----------UPDATE----------
Instead of my previous suggestion, try this:
NSString *csvString = #"333";
NSString *charSet = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.,";
NSScanner *typeScanner = [NSScanner scannerWithString: csvString];
[typeScanner setCharactersToBeSkipped: [NSCharacterSet characterSetWithCharactersInString:charSet]];
NSString *checkString = [[NSString alloc] init];
[typeScanner scanString:csvString intoString:&checkString];
if([csvString length] == [checkString length]){
//the string "csvString" is an integer
}
To check for other types (float, string, etc.), change this line (which checks for int type) NSString *charSet = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.,"; to NSString *charSet = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; (which checks for float type) or NSString *charSet = #"1234567890"; (which checks for a string composed only of letters).
-------Initial Post-------
You could do this:
NSString *stringToTest = #"123";
NSCharacterSet *intValueSet = [NSCharacterSet decimalDigitCharacterSet];
NSArray *test = [stringToTest componentsSeparatedByCharactersInSet:intValueSet];
if ([test count]==[stringToTest length]+1){
NSLog(#"It's an int!");
}
else {
NSLog(#"It's not an int");
}
This works for numbers that don't have a decimal point or commas as thousands separators, like "8493" and "883292837". I've tested it and it works.
Hope this provides a start for you! I'll try to figure out how to test for numbers with decimal points and strings.
Like Andrew said, regular expressions are probably good for this, but they're a bit complicated.

Get Unicode point of NSString and put that into another NSString

What's the easiest way to get the Unicode value from an NSString? For example,
NSString *str = "A";
NSString *hex;
Now, I want to set the value of hex to the Unicode value of str (i.e. 0041)... How would I go about doing that?
The unichar type is defined to be a 16-bit unicode value (eg, as indirectly documented in the description of the %C specifier), and you can get a unichar from a given position in an NSString using characterAtIndex:, or use getCharacters:range: if you want to fill a C array of unichars from the NSString more quickly than by querying them one by one.
NSUTF32StringEncoding is also a valid string encoding, as are a couple of endian-specific variants, in case you want to be absolutely future proof. You'd get a C array of those using the much more longwinded getBytes:maxLength:usedLength:encoding:options:range:remainingRange:.
EDIT: so, e.g.
NSString *str = #"A";
NSLog(#"16-bit unicode values are:");
for(int index = 0; index < [str length]; index++)
NSLog(#"%04x", [str characterAtIndex:index]);
You can use
NSData * u = [str dataUsingEncoding:NSUnicodeStringEncoding];
NSString *hex = [u description];
You may replace NSUnicodeStringEncoding by NSUTF8StringEncoding, NSUTF16StringEncoding (the same as NSUnicodeStringEncoding) or NSUTF32StringEncoding, or many other values.
See here
for more

Split an NSString to access one particular piece

I have a string like this: #"10/04/2011" and I want to save only the "10" in another string. How can I do that?
NSArray* foo = [#"10/04/2011" componentsSeparatedByString: #"/"];
NSString* firstBit = [foo objectAtIndex: 0];
Update 7/3/2018:
Now that the question has acquired a Swift tag, I should add the Swift way of doing this. It's pretty much as simple:
let substrings = "10/04/2011".split(separator: "/")
let firstBit = substrings[0]
Although note that it gives you an array of Substring. If you need to convert these back to ordinary strings, use map
let strings = "10/04/2011".split(separator: "/").map{ String($0) }
let firstBit = strings[0]
or
let firstBit = String(substrings[0])
Either of these 2:
NSString *subString = [dateString subStringWithRange:NSMakeRange(0,2)];
NSString *subString = [[dateString componentsSeparatedByString:#"/"] objectAtIndex:0];
Though keep in mind that sometimes a date string is not formatted properly and a day ( or a month for that matter ) is shown as 8, rather than 08 so the first one might be the worst of the 2 solutions.
The latter should be put into a separate array so you can actually check for the length of the thing returned, so you do not get any exceptions thrown in the case of a corrupt or invalid date string from whatever source you have.
Its working fine
NSString *dateString = #"10/10/2010";//Date
NSArray* dateArray = [dateString componentsSeparatedByString: #"/"];
NSString* dayString = [dateArray objectAtIndex: 0];
Objective-c:
NSString *day = [#"10/04/2011" componentsSeparatedByString:#"/"][0];
Swift:
var day: String = "10/04/2011".componentsSeparatedByString("/")[0]
Use [myString componentsSeparatedByString:#"/"]
I have formatted the nice solution provided by JeremyP above into a more generic reusable function below:
///Return an ARRAY containing the exploded chunk of strings
+(NSArray*)explodeString:(NSString*)stringToBeExploded WithDelimiter:(NSString*)delimiter
{
return [stringToBeExploded componentsSeparatedByString: delimiter];
}
Swift 3.0 version
let arr = yourString.components(separatedBy: "/")
let month = arr[0]

Replacing one character in a string in Objective-C

Hoping somebody can help me out - I would like to replace a certain character in a string and am wondering what is the best way to do this?
I know the location of the character, so for example, if I want to change the 3rd character in a string from A to B - how would I code that?
If it is always the same character you can use:
stringByReplacingOccurrencesOfString:withString:
If it is the same string in the same location you can use:
stringByReplacingOccurrencesOfString:withString:options:range:
If is just a specific location you can use:
stringByReplacingCharactersInRange:withString:
Documentation here:
https://developer.apple.com/documentation/foundation/nsstring
So for example:
NSString *someText = #"Goat";
NSRange range = NSMakeRange(0,1);
NSString *newText = [someText stringByReplacingCharactersInRange:range withString:#"B"];
newText would equal "Boat"
NSString *str = #"123*abc";
str = [str stringByReplacingOccurrencesOfString:#"*" withString:#""];
//str now 123abc
Here is the code:
[aString stringByReplacingCharactersInRange:NSMakeRange(3,1) withString:#"B"];
Use the replaceCharactersInRange: withString: message on a NSMutableString object.

Finding a substring in a NSString object

I have an NSString object and I want to make a substring from it, by locating a word.
For example, my string is: "The dog ate the cat", I want the program to locate the word "ate" and make a substring that will be "the cat".
Can someone help me out or give me an example?
Thanks,
Sagiftw
NSRange range = [string rangeOfString:#"ate"];
NSString *substring = [[string substringFromIndex:NSMaxRange(range)] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSString *str = #"The dog ate the cat";
NSString *search = #"ate";
NSString *sub = [str substringFromIndex:NSMaxRange([str rangeOfString:search])];
If you want to trim whitespace you can do that separately.
What about this way?
It's nearly the same.
But maybe meaning of NSRange easier to understand for beginners, if it's written this way.
At last, it's the same solution of jtbandes
NSString *szHaystack= #"The dog ate the cat";
NSString *szNeedle= #"ate";
NSRange range = [szHaystack rangeOfString:szNeedle];
NSInteger idx = range.location + range.length;
NSString *szResult = [szHaystack substringFromIndex:idx];
Try this one..
BOOL isValid=[yourString containsString:#"X"];
This method return true or false. If your string contains this character it return true, and otherwise it returns false.
NSString *theNewString = [receivedString substringFromIndex:[receivedString rangeOfString:#"Ur String"].location];
You can search for a string and then get the searched string into another string...
-(BOOL)Contains:(NSString *)StrSearchTerm on:(NSString *)StrText
{
return [StrText rangeOfString:StrSearchTerm options:NSCaseInsensitiveSearch].location==NSNotFound?FALSE:TRUE;
}
You can use any of the two methods provided in NSString class, like substringToIndex: and substringFromIndex:. Pass a NSRange to it as your length and location, and you will have the desired output.