#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
       
        //1⃣️.通过C的字符串
        
        //C --> OC
        
        char *cString = "cString";
        
        NSString *ocStr1 = [[NSString alloc]initWithUTF8String:cString];
        
        NSString *ocStr2 = [NSString stringWithUTF8String:cString];
        
        NSString *ocStr3 = [NSString stringWithCString:cString encoding:NSUTF8StringEncoding];
        
        NSLog(@"%@",ocStr1);
        
        NSLog(@"%@",ocStr2);
        
        NSLog(@"%@",ocStr3);
        
        //OC --> C
        const char *cStr = [ocStr1 UTF8String];
        
        NSLog(@"%s",cStr);
        
        //2⃣️.初始化
        
        //1.实例方法
        
        //快速创建:更改字符串 --> 更改了指针的指向地址
        NSString *string = @"string";
        
        string = @"我得字幕组啊";
        
        NSString *str2 = [[NSString alloc]initWithFormat:@"%@唱战歌!",string];
        
        NSLog(@"%@",str2);
        
        //2.类方法
        
        NSString *str4 = [NSString stringWithFormat:@"%d %@ %f",99,string,66.66];
        
        NSLog(@"%@",str4);
        
        //3⃣️属性
        
        NSUInteger length = string.length;
        
        NSLog(@"%ld",length);
        
        //4⃣️方法
        
        //判断字符串的内容是否相同
        BOOL isEqual = [string isEqualToString:str2];
        
        NSLog(@"%d",isEqual);
        
        //判断字符串的地址是否相同
        NSLog(@"%@",(str2 == str4)?@"地址相同":@"地址不同");
        
        //比较字符串的大小 --> 升序   相同  降序
        NSComparisonResult result = [@"bbb"caseInsensitiveCompare:@"aaa"];
        
        switch (result) {
            case NSOrderedAscending:
                NSLog(@"升序");
                break;
                
            case NSOrderedSame:
                NSLog(@"平序");
                break;
                
            case NSOrderedDescending:
                NSLog(@"降序");
                break;
                
            default:
                break;
        }
        
        //√ 转换:大小字母转换
        NSString *str5 = @"qwerQAQ";
        
        //1.全部变大写字母
        NSLog(@"%@",[str5 uppercaseString]);
        
        //2.全部变小写字母
        NSLog(@"%@",[str5 lowercaseString]);
        
        //3.首字母大写 --> 每个单词的首字母大写,其他小写
        NSLog(@"%@",[str5 capitalizedString]);
        
        //str5还是原来的
        NSLog(@"%@",str5);
        
        //√ 转化:基本数据类型
        NSString *str6 = @"10086";
        
        int intS = [str6 intValue];
        NSInteger intsS = [str6 integerValue];
        float floS = [str6 floatValue];
        double douS = [str6 doubleValue];
        BOOL boolS = [str6 boolValue];
        
        NSLog(@"%d",intS);
        NSLog(@"%ld",intsS);
        NSLog(@"%f",floS);
        NSLog(@"%lf",douS);
        NSLog(@"%d",boolS);
        
        //字符串的截取
        
        //1.分割
        
        NSString *urlString = @"www.a4yy.com";
        
        //将参数作为分隔符,将字符串分割成若干部分
        NSArray *array = [urlString componentsSeparatedByString:@"."];
        
        NSLog(@"%@",array);
        
        //2.获取字符串
        char character = [urlString characterAtIndex:4];
        
        NSLog(@"%c",character);
        
        //3.截取substring
        
            //截取到下标(不包括下标字符)
        NSLog(@"%@",[urlString substringToIndex:5]);
        
            //自下标截取(包括下标字符)
        NSLog(@"%@",[urlString substringFromIndex:5]);
        
        //OC创建结构体
        NSRange range = NSMakeRange(4, 5);
        
        NSLog(@"%@",[urlString substringWithRange:range]);
        
        //4.拼接 appending
        NSString *appString = @"南山南";
        
            //拼接字符串
        NSLog(@"%@",[appString stringByAppendingString:@"北秋悲"]);
        
            //拼接格式化字符串
        NSLog(@"%@",[appString stringByAppendingFormat:@"最丑不过%@",@"卢本伟"]);
        
            //拼接扩展名 .pdf
        NSLog(@"%@",[appString stringByAppendingPathExtension:@"dmg"]);
        
            //拼接路径 /path
        NSLog(@"%@",[appString stringByAppendingPathComponent:@"dmg"]);
        
        //5.查找
        NSString *findString = @"/Users/CORYIL/Library/Developer/CoreSimulator/Devices/88A633A0-6294-4853-80DE-8060C1580820/data/Containers/Data/Application/84CE535F-49D1-498E-89DB-2F07C50D6A24/Documents/";
        
        NSRange findResult = [findString rangeOfString:@"Documents"];
        
        //将结构体转化为字符串 NSStringFromXXX(结构体)
        NSLog(@"%@",NSStringFromRange(findResult));
        
        //替换 replacing
        
            //根据range替换
        NSString *newString = [findString stringByReplacingCharactersInRange:findResult withString:@"黑黑"];
        
        NSLog(@"%@",newString);
        
            //直接替换
        NSLog(@"%@",[findString stringByReplacingOccurrencesOfString:@"Users" withString:@"用户们"]);
        
        
    }
    return 0;
}

NSL…
2016-02-18 11:25:07.816 NSString[1162:64272] cString
2016-02-18 11:25:07.818 NSString[1162:64272] cString
2016-02-18 11:25:07.818 NSString[1162:64272] cString
2016-02-18 11:25:07.819 NSString[1162:64272] cString
2016-02-18 11:25:07.819 NSString[1162:64272] 我得字幕组啊唱战歌!
2016-02-18 11:25:07.820 NSString[1162:64272] 99 我得字幕组啊 66.660000
2016-02-18 11:25:07.820 NSString[1162:64272] 6
2016-02-18 11:25:07.820 NSString[1162:64272] 0
2016-02-18 11:25:07.820 NSString[1162:64272] 地址不同
2016-02-18 11:25:07.821 NSString[1162:64272] 降序
2016-02-18 11:25:07.821 NSString[1162:64272] QWERQAQ
2016-02-18 11:25:07.821 NSString[1162:64272] qwerqaq
2016-02-18 11:25:07.822 NSString[1162:64272] Qwerqaq
2016-02-18 11:25:07.822 NSString[1162:64272] qwerQAQ
2016-02-18 11:25:07.822 NSString[1162:64272] 10086
2016-02-18 11:25:07.822 NSString[1162:64272] 10086
2016-02-18 11:25:07.822 NSString[1162:64272] 10086.000000
2016-02-18 11:25:07.823 NSString[1162:64272] 10086.000000
2016-02-18 11:25:07.823 NSString[1162:64272] 1
2016-02-18 11:25:07.823 NSString[1162:64272] (
    www,
    a4yy,
    com
)
2016-02-18 11:25:07.823 NSString[1162:64272] a
2016-02-18 11:25:07.824 NSString[1162:64272] www.a
2016-02-18 11:25:07.824 NSString[1162:64272] 4yy.com
2016-02-18 11:25:07.824 NSString[1162:64272] a4yy.
2016-02-18 11:25:07.824 NSString[1162:64272] 南山南北秋悲
2016-02-18 11:25:07.824 NSString[1162:64272] 南山南最丑不过卢本伟
2016-02-18 11:25:07.825 NSString[1162:64272] 南山南.dmg
2016-02-18 11:25:07.825 NSString[1162:64272] 南山南/dmg
2016-02-18 11:25:07.825 NSString[1162:64272] {161, 9}
2016-02-18 11:25:07.825 NSString[1162:64272] /Users/CORYIL/Library/Developer/CoreSimulator/Devices/88A633A0-6294-4853-80DE-8060C1580820/data/Containers/Data/Application/84CE535F-49D1-498E-89DB-2F07C50D6A24/黑黑/
2016-02-18 11:25:07.826 NSString[1162:64272] /用户们/CORYIL/Library/Developer/CoreSimulator/Devices/88A633A0-6294-4853-80DE-8060C1580820/data/Containers/Data/Application/84CE535F-49D1-498E-89DB-2F07C50D6A24/Documents/
Program ended with exit code: 0