nsstring

The code below compiles and runs, BUT according to all iPhone development books and Apple documentation it shouldnt! Can someone please explain to me how come immutable NSString allows to change its values after it has been set? I thought I had to use NSMuttableString to change context of the same string variable? I am using SDK 3.1. NSString *test =[[NSString alloc] initWithString:@"TEST"]; [test release]; test = @"TEST2"; Perhaps the following example will add upon the replies from Mark and Niels and help clarify things. Immutable strings // Setup two variables to point to the same string

I'm pulling a listing of results from a SQLite3 database into a UITableView . The code where I pull text from the database is like so: char *menuNameChars = (char *) sqlite3_column_text(statement, 1); NSString *menuName = [[NSString alloc] initWithUTF8String:menuNameChars]; NSLog(@"Retrieved %s,%@ from DB.", menuNameChars, menuName); When I use initWithUTF8String , sometimes the information is copied properly from the database. Sometimes though, the information is displayed properly from the char* , but not from the NSString : 2011-10-24 22:26:54.325 [23974:207] Retrieved Cravin Chicken

Help me to write the code like "if my string is a valid URL do smth" Is it possible to write this in a couple strings of code? I will assume that by URL, you are referring to a string identifying a internet resource location. If you have an idea about the format of the input string , then why not manually check if the string starts with http:// , https:// or any other scheme you need. If you expect other protocols, you can also add them to the check list (e.g. ftp:// , mailto:// , etc) if ([myString hasPrefix:@"http://"] || [myString hasPrefix:@"https://"]) { // do something } If you are

NSString *myString = @"sample string"; NSString *newString = [myString copy]; If I set a breakpoint after these two lines, the pointer for myString is the same as the pointer for newString. WTF? Isn't NSString copy supposed to return a pointer to a new object? Or am I missing something fundamental about how copy is supposed to work? Since NSString is not mutable it might just internally increase ref count and be done with it. When you release one of those NSStrings it might just decrement ref count - standard memory management. Do you see any issues with that? Think about this: NSMutableString

When I alloc and init two NSString variables and compare their pointers, they are the same. Here's a snippet that shows this: NSString *s1 = [[NSString alloc] initWithString:@"hello world"]; NSString *s2 = [[NSString alloc] initWithString:@"hello world"]; if (s1 == s2) { NSLog(@"=="); }else { NSLog(@"!="); } Why are s1 and s2 the same? There are three things going on here: Firstly, the two identical string literals you're passing in to initWithString: will have the same address to start. This is an obvious optimization for constant data. Secondly, when you nest alloc and init with strings, the

I have just localized the file Localizable.strings in my Xcode project in order to localise my application to a few different languages. However, having edited each of the files in the standard "key = value" format, I receive the following parsing error, which does not specify a file making it hard to track down what it is referring to. CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 10. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug. I have looked through each of the *.strings files, specifically on line 10, and