1. 第一个OC程序
- 打开
xcode
Create a new Xcode project-macOS-Command Line Tool -
NSLog打印
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
// insert code here...
NSLog(@"Hello, World!");
}
return 0;
}
2. 基础语法
- 整型、浮点型、布尔型
#import <Foundation/Foundation.h>
//这时main函数
int main(int argc, const char * argv[]) {
@autoreleasepool {
// insert code here...
NSLog(@"Hello, World!");
// 整型
int a = 10;
NSLog(@"%d", a); //打印整型 10
double b = 10.1;
NSLog(@"%f", b); //打印浮点型 10.10000
BOOL c = TRUE;
NSLog(@"%hhd", c); //打印布尔型 1
NSInteger d = 3; //NSInteger会自动选择 int或者long
NSLog(@"%ld", (long)d); //3
}
return 0;
}
3. 字符串、数组、字典
- 字符串
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
NSString *str = @"Hello oc";
//打印长度
NSLog(@"%lu", (unsigned long)str.length); //8
//字符串拼接
NSLog(@"%@", [NSString stringWithFormat:@"%@-%d", str, 10]); //Hello oc-10
//大小写转换
NSLog(@"%@", [str uppercaseString]); //HELLO OC
//截取字符串
NSLog(@"%@", [str substringFromIndex: 2]); //llo oc
NSLog(@"%@", [str substringToIndex: 2]); //He
NSLog(@"%@", [str substringWithRange: NSMakeRange(2, 3)]); //llo
//替换字符串
NSLog(@"%@", [str stringByReplacingOccurrencesOfString: @"o" withString:@"*"]); //Hell* *c
}
return 0;
}
- 数组
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
NSArray *array = @[@1, @2.0, @"abc"];
NSLog(@"%@", array[1]); //2
//for in循环
for(id item in array) {
NSLog(@"%@", item);
}
//for循环
for(int i=0; i < array.count; i++) {
NSLog(@"%d-%@",i, array[i]); //0-1 1-2 2-abc
}
//通过元素找下标
NSLog(@"%lu", [array indexOfObject:@"abc"]); //2
//可变数组
NSMutableArray *muArray = [NSMutableArray arrayWithArray:array];
//添加元素
[muArray addObject:@"de"];
//删除元素
[muArray removeObject: @1];
for(id item in muArray) {
NSLog(@"%@", item); //2 abc de
}
}
return 0;
}
- 字典
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
NSDictionary *dir = @{
@"name": @"张三",
@"age": @"18",
@"sex": @"male"
};
for (NSString *key in [dir allKeys]) {
NSLog(@"%@-%@", key, [dir valueForKey:key]); //name-张三 age-18 sex-male
}
for (NSString *value in [dir allValues]) {
NSLog(@"%@", value); //张三 18 male
}
}
return 0;
}
4. 面向对象
- 第一个面向对象程序
// Person.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface Person : NSObject
//属性
@property(copy, nonatomic) NSString *name;
@property(copy, nonatomic) NSString *sex;
@property(assign, nonatomic) NSInteger *age;
@property(strong, nonatomic) NSArray *children;
//方法
//+表示静态方法，-表示实例方法。
//:之后为参数
+(void)say;
-(void)eat:(NSString *)food;
-(NSString *)sleep:(NSString *)time;
@end
NS_ASSUME_NONNULL_END
// Person.m
#import "Person.h"
@implementation Person
+(void)say {
NSLog(@"说话");
}
-(void)eat:(NSString *)food {
NSLog(@"吃%@", food);
}
-(NSString *)sleep:(NSString *)time {
NSLog(@"%@点睡觉", time);
return @"睡着了";
}
@end
// main.m
#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
Person *p= [[Person alloc]init];
p.age = 10;
p.sex = @"male";
p.name = @"zhangsan";
p.children = @[@"张三", @"李四"];
[Person say]; //说话
[p eat:@"苹果"]; //吃苹果
NSLog(@"%@", [p sleep:@"11"]); //11点睡觉 睡着了
}
return 0;
}
- 继承与多态
// Student.h
#import <Foundation/Foundation.h>
#import "Person.h"
NS_ASSUME_NONNULL_BEGIN
@interface Student : Person
@property(copy, nonatomic) NSString *stuNo;
@end
NS_ASSUME_NONNULL_END
// Student.m
#import "Student.h"
@implementation Student
-(NSString *)sleep:(NSString *)time {
NSLog(@"学生%@点睡觉", time);
return @"学生睡着了";
}
@end
// main.m
#import <Foundation/Foundation.h>
#import "Person.h"
#import "Student.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
[Student say]; //说话
Student *stu = [[Student alloc]init];
stu.stuNo = @"001";
[stu eat:@"苹果"]; //吃苹果
NSLog(@"%@", [stu sleep:@"11"]); //学生11点睡觉 学生睡着了
Person *stu2 = [[Student alloc]init]; //多态
NSLog(@"%@", [stu2 sleep:@"10"]); //学生10点睡觉 学生睡着了
}
return 0;
}
-
get与set方法
get与set方法不能同时定义
//Student.m
#import "Student.h"
@implementation Student
-(void)setStuNo:(NSString *)stuNo{
_stuNo = stuNo;
NSLog(@"set StuNo");
}
-(NSString *)stuNo{
NSLog(@"set StuNo");
return _stuNo;
}
@end
- 私有方法
在.m中定义，没有在.h中声明的方法为私有方法。
//Student.m
#import "Student.h"
@implementation Student
-(void)study{
NSLog(@"好好学习");
}
-(NSString *)sleep:(NSString *)time {
[self study];
//...
}
@end
description
// Student.m
#import "Student.h"
@implementation Student
- (NSString *)description
{
return [NSString stringWithFormat:@"当前学生的信息为%@", self.stuNo];
}
@end
// main.m
#import <Foundation/Foundation.h>
#import "Student.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
Student *stu = [[Student alloc]init];
stu.stuNo = @"001";
NSLog(@"%@", stu); //当前学生的信息为001
}
return 0;
}
- 构造函数
// Person.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface Person : NSObject
//属性
@property(copy, nonatomic) NSString *name;
@property(copy, nonatomic) NSString *sex;
@property(assign, nonatomic) NSInteger *age;
@property(strong, nonatomic) NSArray *children;
-(instancetype)initWithName:(NSString *)name Sex:(NSString *)sex Age:(NSInteger)age Children:(NSArray *)children;
@end
NS_ASSUME_NONNULL_END
// Person.m
#import "Person.h"
@implementation Person
-(instancetype)initWithName:(NSString *)name Sex:(NSString *)sex Age:(NSInteger)age Children:(NSArray *)children{
if(self = [super init]){
self.name = name;
self.sex = sex;
self.age = age;
self.children = children;
}
return self;
}
@end
// main.m
#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
Person *p2= [[Person alloc]initWithName:@"李四" Sex:@"female" Age:12 Children:@[@"A", @"B"]];
NSLog(@"%@", p2.name);
NSLog(@"%@", p2.sex);
NSLog(@"%d", p2.age);
NSLog(@"%@", p2.children);
}
return 0;
}
5. 高级语法
-
category分类
第一种扩展
New File-Objective-C File-File Type: Category、Class: NSString
// NSString+Hello.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface NSString (Hello)
-(void) say;
@end
NS_ASSUME_NONNULL_END
// NSString+Hello.m
#import "NSString+Hello.h"
@implementation NSString (Hello)
-(void) say{
NSLog(@"Hello");
}
@end
// main.m
#import <Foundation/Foundation.h>
#import "NSString+Hello.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
NSString *str = @"abc";
[str say]; //Hello
}
return 0;
}
第二种扩展
// Person.m
#import "Person.h"
@interface Person()
@end
@implementation Person
@end
-
protocol协议
New File - Objective-C File - File Type: Protocal
// buyTicket.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@protocol buyTicket <NSObject>
@required
-(void)buy;
@optional
-(void)sell;
@end
NS_ASSUME_NONNULL_END
// AClass.h
#import <Foundation/Foundation.h>
#import "buyTicket.h"
NS_ASSUME_NONNULL_BEGIN
@interface AClass : NSObject <buyTicket>
@end
NS_ASSUME_NONNULL_END
// AClass.m
#import "AClass.h"
@implementation AClass
-(void)buy{
NSLog(@"A买票");
}
@end
// BClass.h
#import <Foundation/Foundation.h>
#import "buyTicket.h"
NS_ASSUME_NONNULL_BEGIN
@interface BClass : NSObject <buyTicket>
@end
NS_ASSUME_NONNULL_END
// BClass.m
#import "BClass.h"
@implementation BClass
-(void)buy{
NSLog(@"B买票");
}
@end
// Boss.h
#import <Foundation/Foundation.h>
#import "buyTicket.h"
NS_ASSUME_NONNULL_BEGIN
@interface Boss : NSObject
@property (weak, nonatomic) id<buyTicket> tickerDelegate;
-(void)buyTicket;
@end
NS_ASSUME_NONNULL_END
// Boss.m
#import "Boss.h"
@implementation Boss
-(void)buyTicket{
if([self.tickerDelegate respondsToSelector:@selector(buy)]) {
[self.tickerDelegate buy];
}
}
@end
// main.m
// 协议
#import <Foundation/Foundation.h>
#import "Boss.h"
#import "AClass.h"
#import "BClass.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
//代理模式
Boss *boss = [[Boss alloc]init];
AClass *a = [[AClass alloc]init];
BClass *b = [[BClass alloc]init];
boss.tickerDelegate = a;
[boss buyTicket]; //A买票
boss.tickerDelegate = b;
[boss buyTicket]; //B买票
}
return 0;
}
Block
#import <Foundation/Foundation.h>
typedef int(^Block2)(int, int);
int main(int argc, const char * argv[]) {
@autoreleasepool {
//第一种创建方式
int(^myBlock)(int, int) = ^(int a, int b){
return a + b;
};
int b = myBlock(2, 5);
NSLog(@"%d", b); //7
//第二种创建方式
Block2 block2 = ^(int a, int b){
return a * b;
};
int b2 = block2(2, 5);
NSLog(@"%d", b2); //10
//可以修改__block修饰的变量
__block int n = 3;
void(^block3)() = ^(){
n *= 2;
};
block3();
NSLog(@"%d", n); //6
}
return 0;
}
如果在block中使用self，self中的类又包含block属性，这样会造成循环引用。
可以通过将self转化为一个用__weak修饰的weakSelf，避免循环引用。
Foundation
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
//结构体
CGPoint point = CGPointMake(200, 200);
CGSize size = CGSizeMake(200, 200);
CGRect rect = CGRectMake(0, 0, 200, 300);
//NSValue
NSNumber *number = [NSNumber numberWithInt:20];
[number intValue];
NSValue *v1 = [NSValue valueWithPoint:point];
NSValue *v2 = [NSValue valueWithSize:size];
NSValue *v3 = [NSValue valueWithRect:rect];
NSArray *arr = @[v1, v2, v3];
//NSDate
NSDate *date = [[NSDate alloc]init];
NSLog(@"%@", date); //Mon Mar 8 21:03:10 2021
NSDateFormatter *formatdate = [[NSDateFormatter alloc]init];
formatdate.dateFormat = @"yyyy/MM/dd HH:mm:ss";
NSLog(@"%@", [formatdate stringFromDate:date]); //2021/03/08 21:06:56
}
return 0;
}
KVC
// Person.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface Person : NSObject
@property (nonatomic, copy, readonly) NSString *name;
@end
NS_ASSUME_NONNULL_END
// main.m
#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
Person *p = [[Person alloc]init];
//p.name = @"张三"; //Assignment to readonly property
//NSLog(@"%@", p.name);
[p setValue:@"张三" forKey:@"name"];
NSLog(@"%@", [p valueForKey: @"name"]); //张三
}
return 0;
}
