Tagged Questions
68
votes
3answers
57k views
AES Encryption for an NSString on the iPhone
Can anybody point me in the right direction to be able to encrypt a string, returning another string with the encrypted data? (I've been trying with AES256 encryption.) I want to write a method which ...
217
votes
10answers
158k views
How to convert an NSString into an NSNumber
How can I convert a NSString containing a number of any primitive data type (e.g. int, float, char, unsigned int, etc.)? The problem is, I don't know which number type the string will contain at ...
84
votes
10answers
83k views
Objective-C: Reading a file line by line
What is the appropriate way of dealing with large text files in Objective-C? Let's say I need to read each line separately and want to treat each line as an NSString. What is the most efficient way of ...
43
votes
6answers
35k views
Converting NSString to NSDate (and back again)
How would I convert an NSString like "01/02/10" (meaning 1st February 2010) into an NSDate? And how could I turn the NSDate back into a string?
27
votes
5answers
24k views
Understanding NSString comparison
Both the following comparisons evaluate to true:
1)
@"foo" == @"foo";
2)
NSString *myString1 = @"foo";
NSString *myString2 = @"foo";
myString1 == myString2;
However, there are definitely times ...
49
votes
12answers
20k views
Remove all but numbers from NSString
I have an NSString (phone number) with some parenthesis and hyphens as some phone numbers are formatted. How would I remove all characters except numbers from the string?
44
votes
14answers
45k views
iPhone how to check that a string is numeric only
How do I validate the string input from a UITextField? I want to check that the string is numeric, including decimal points.
22
votes
2answers
19k views
9
votes
5answers
22k views
Comparing Strings in Cocoa
I have tried:
- (NSString*) generateString
{
NSString* stringToReturn = @"thisString";
return stringToReturn;
}
- (void) otherMethod
{
NSString *returnedString = [self generateString];
...
29
votes
7answers
16k views
Objective-C url encoding
I have a NSString like this:
http://www.
but I want to transform it to:
http%3A%2F%2Fwww.
How can I do?
thanks
16
votes
11answers
20k views
Number of occurrences of a substring in an NSString?
How can I get the number of times an NSString (for example, @"cake") appears in a larger NSString (for example, @"Cheesecake, apple cake, and cherry pie")?
I need to do this on a lot of strings, so ...
82
votes
12answers
49k views
Collapse sequences of white space into a single character
Consider the following example:
" Hello this is a long string! "
I want to convert that to:
"Hello this is a long string!"
11
votes
5answers
1k views
Difference between NSString literals
What is the difference between these two lines?
NSString * string = @"My String";
NSString * string = [[[NSString alloc] initWithString:@"MyString"] autorelease]
4
votes
2answers
3k views
How to make subscripts and superscripts using NSAttributedString?
I need to make subscripts for chemistry formulas (H2O, Na^2+, etc)?
Is this possible to do with NSAttributedString, or is there an alternative/easier way to make subscripts?
15
votes
3answers
6k views
What is the maximum length of an NSString object?
What is the maximum sized string that can be held in a NSString object?
Does this change dynamically?
