How to create a string in objective-C?
The simplest way to create a string object in source code is to use the Objective-C @”…” construct: NSString *temp = @”Contrafibularity”; Note, when creating a string constant in this fashion, you should use UTF-8 characters.
How to convert string to char in objective-C?
To convert NSString to const char use -[NSString UTF8String] : NSString *myNSString = @”Some string”; const char *cString = [myNSString UTF8String]; You could also use -[NSString cStringUsingEncoding:] if your string is encoded with something other than UTF-8.
What does an Objective-C string literal look like?
A string literal is a expression like @”” . The compiler will replace this with an instance of NSString . A string constant is a read-only pointer to NSString .
What is NSString in objective-C?
Like NSNumber, NSString is also immutable type. It’s used to represent text in Objective-C. NSString provides built-in support for Unicode, which means that we can include UTF-8 characters directly in string literals.
How do you count strings in Objective-C?
int len = [myString length];
How do I check if a string contains a substring in Objective-C?
To check if a string contains another string in objective-c, we can use the rangeOfString: instance method where it returns the {NSNotFound, 0} if a ‘searchString’ is not found or empty (“”). Output: string contains you!
What is the difference between and in Objective-C?
Objective C was developed in early 1980s by Brad Cox and Tom Love. It is an object-oriented, general purpose language and was created with the vision of providing small talk-style messaging to the C programming language….Difference between C and Objective C.
| C Language | Objective C |
|---|---|
| It supports only pointers. | It supports both pointers and references. |
What is NSNumber in Objective-C?
NSNumber is a subclass of NSValue that offers a value as any C scalar (numeric) type. It defines a set of methods specifically for setting and accessing the value as a signed or unsigned char , short int , int , long int , long long int , float , or double or as a BOOL .
What is difference between string and NSString in Swift?
Secondly, in Swift String is a struct, while in Objective-C, NSString is a class and inherit from NSObject . In concept, Swift String is more likely immutable. If we use a struct type and constant (remember the let keyword), we can keep out a lot of consideration of multi-thread programming and make us a better life.
What is NSObject in Swift?
The root class of most Objective-C class hierarchies, from which subclasses inherit a basic interface to the runtime system and the ability to behave as Objective-C objects.
What is Objective-C tutorial?
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. This is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch.
Should I use wchar_t when dealing with UTF-8 in C++?
My platform is a Mac. I’m a C++ beginner and working on a personal project which processes Chinese and English. UTF-8 is the preferred encoding for this project. I read some posts on Stack Overflow, and many of them suggest using std::string when dealing with UTF-8 and avoid wchar_t as there’s no char8_t right now for UTF-8.
What string types are already UTF-8 on macOS?
On most platforms including macOS that you are using normal char strings are already UTF-8. Most of the standard string operations work with UTF-8 but operate on code units.
What is UTF-8 and why should I care about it?
UTF-8 actually works quite well in std::string. Most operations work out of the box because the UTF-8 encoding is self-synchronizing and backward compatible with ASCII. Due the way Code Points are encoded, looking for a Code Point cannot accidentally match the middle of another Code Point:
How many bytes does UTF-8 take?
UTF-8 is a multibyte encoding which uses between 1 and 4 bytes per character. So, it is safer to use 40 as the buffer size above. There is a big discussion at How many bytes does one Unicode character take? which might be interesting.