iOS/Objective-C

[Objective-C] Variables and constants / Paul Hudson의 Objective-C cheat sheet

TDCIAN 2023. 4. 8. 20:54

 

사진에 원본 링크 걸어놨습니다!

 

1. Variables and constants

 

(1) Variable

// Create a variable
NSInteger score = 556;
// var score = 556
NSString *name = @"Taylor";
// var name = "Taylor"
BOOL loggedIn = NO;
// var loggedIn = false
view raw objc_variable.m hosted with ❤ by GitHub

(2) Constant

// Create a constant
const NSInteger score = 556;
// let score = 556
NSString * const name = @"Taylor";
// let name = "Taylor"
const BOOL firstRun = YES;
// let firstRun = true
/*
Constants are used infrequently in Objective-C,
but extremely common in Swift
*/
view raw objc_constant.m hosted with ❤ by GitHub

 

 

(3) Variable array

// Create a variable array
NSMutableArray *items = [NSMutableArray new];
// var items = [String]()
NSMutableArray<NSString *> *results = [NSMutableArray new];
// var results = Array<String>()

(4) Constant array

// Create a constant array
NSArray *grades = @[@90, @85, @97];
// let grades = [90, 85, 97]
NSArray *names = @[@"Talyor", @"Adele", @"Justin"];
// let names = ["Talyor", "Adele", "Justin"]

(5) Adding a value type to an array

// Adding a value type to an array
NSMutableArray *array = [NSMutableArray new];
// var array = [CGRect]()
[array addObject:[NSValue valueWithRect:CGRectMake(0, 0, 32, 64)]];
// array.append(CGRect(x: 0, y: 0, width: 32, height: 64))
/*
Value types must be wrapped in a reference type before being added to a collection.
*/

 

 

(6) Dictionary

// Create a dictionary
NSDictionary *houseNumbers = @{@"Paul": @7, @"Jess": @56, @"Peter": @332};
// let houseNumbers = ["Paul": 7, "Jess": 56, "Peter": 332]

 

 

(7) Enum

// Define an enum
typedef NS_ENUM(NSInteger, ShapeType) {
kCircle,
kRectangle,
kHexagon
};
/*
enum ShapeType: Int {
case circle
case rectangle
case hexagon
}
*/
view raw objc_enum.m hosted with ❤ by GitHub

 

 

(8) Appending a string

NSString *first = @"Hello, ";
// let first = "Hello, "
NSString *second = [first stringByAppendingString:@" world!"];
// let second = first + "world!"

 

 

(9) Adding to a number

NSInteger rating = 4;
// var rating = 4
rating++;
// rating += 1
rating += 3;
// rating += 3

 

 

(10) String interpolation

NSString *account = @"twostraws";
// let account = "twostraws"
NSString *str = [NSString stringWithFormat:@"Follow me on Twitter: %@", account];
// let str = "Follow me on Twitter: \(account)"

 

 

(11) Printing debug information

NSString *username = @"twostraws";
// let username = "twostraws"
NSLog(@"Username is %@", username);
// print("Username is \(username)")

 

 

참조: 

https://www.hackingwithswift.com/articles/114/objective-c-to-swift-conversion-cheat-sheet

 

Objective-C to Swift conversion cheat sheet

Here is the Rosetta Stone for Objective-C to Swift

www.hackingwithswift.com