iOS开发学习第十六课——如何使用苹果帮助文档、NSString

        如何学好iOS开发?
         1.要学会使用苹果官方文档
         2.对于方法的学习记忆:多练多敲
         3.多查资料
         4.上课对于新方法的学习,一定要做详细注释

         5.***多调试Bug,提升自己独立解决问题的能力

        

#import<Foundation/Foundation.h>

intmain(intargc, const char * argv[]) {

   @autoreleasepool {

       //NSString 字符串类
        //1.创建一个字符串对象
        NSString*str1 = @"XiaoMing";
        //2.创建字符串对象的第二种方法(初始化方法创建)
        //(1).
         NSString*str2 = [[NSStringalloc]initWithString:@"JiangTao"];
        //(2).使用便利构造器创建对象
        NSString*str2 = [[NSString stringWithString:@"峻峰"];
        //3.Format格式
        NSString*str4 = @"帅帅";
        NSString*str5 = [NSStringstringWithFormat:@"我叫%@",str4];
        NSLog(@"str5 = %@",str5);
        //对于基本数据类型也可以使用到字符串当中
        int a = 10;
        NSString*str6 = [NSStringstringWithFormat:@"今年%d岁",a];
        NSLog(@"str6 = %@",str6);
       
        //如何将C语言当中字符串转化为OC对象
        char symbol[10] = "Hello";//C言语当中的字符串
        //将C语言字符串转化OC字符串对象
        NSString*str7 = [NSStringstringWithUTF8String:symbol];
        NSLog(@"str7 = %@",str7);
       
       
        //使用Format格式
        char name[10] = {0};
        printf("请输入同桌的姓名：");
        scanf("%s",name);
        //将C语言里的字符串转化为OC中的字符串对象
        NSString*nameStr = [NSStringstringWithUTF8String:name];
        //使用formate格式 得到最终的字符串
        NSString*classmateStr = [NSStringstringWithFormat:@"My classmate's name is %@",nameStr];
        NSLog(@"%@",classmateStr);
       
       
        //字符串长度
        NSString*str8 = @"You Can You Up,No Can No BB";
       
        //创建字符串对象
        NSString*str8 = [NSString stringWithFormat:@"You Can You Up,No Can No BB!"];
        //求字符串长度 不考虑'\0'
        NSUIntegerlength = [str8 length];
        NSLog(@"Length = %lu",length);
        //汉字
        NSString*ChineseStr = @"小龙吃包子";
        NSUIntegerChineseLength = [ChineseStr length];
        NSLog(@"%lu",ChineseLength);
       
        //3.前缀和后缀 也就是字符串以什么开头,以什么结尾
        //前缀和后缀是没有界限的
        NSString*baiduStr = @"http://www.baidu.com";
        //hasPrefix此方法用来判断字符串前缀,也就是说是否以某字符串开头,返回值类型是BOOL类型,如果为真,则说明字符串是以次前缀开头
        BOOL isStart = [baiduStr hasPrefix:@"http"];
        NSLog(@"isStart = %d",isStart);
        BOOL isEnd = [baiduStr hasSuffix:@"com"];
        NSLog(@"isEnd = %d",isEnd);

       
        //创建一个新浪网址字符串
        char Sina[50] = {0};
        printf("请输入新浪网址:");
        scanf("%s",Sina);
        //将C语言的字符串转化为OC中的对象
        NSString*SinaStr = [NSStringstringWithUTF8String:Sina];
        //判断前缀是否以http.开头
        BOOL SinaStart = [SinaStr hasPrefix:@"www."];
        //判断后缀是否以.com结尾
        BOOL SinaEnd = [SinaStr hasSuffix:@".com"];
        //如果同时满足前缀和后缀,则说明是有效网址
        if (SinaStart && SinaEnd) {
            NSLog(@"此网址是有效网址");
        }else{//否则是无效网址
            NSLog(@"此网址是无效网址");
        }
       
        
        
        //4.搜索字符串范围
        NSString*rangOfStr = @"ZhenZhe XiaoLong HaiFeng";
        //rangeOfString用来求字符串中子字符串的范围
        NSRangerange = [rangOfStr rangeOfString:@"XiaoLong"];
        //NSRang是一个结构体,成员有location和 length ,所以rang.location是字符串范围的下标起始位置,而且,如果字符串有两个及两个以上的话,以遇到第一个为准
        NSLog(@"location = %lu,length = %lu",(unsignedlong)range.location,(unsignedlong)range.length);
        //因为子字符串当中可以得到长度,如果不存在此字符串,则length == 0,所以,我们通过length的结果判断此时字符串中有没有我们需要的子字符串(字符串当中的内容)
        if (range.length!= 0){
            NSLog(@"查找成功,存在此字符串");
        }else{
            NSLog(@"查找不成功,不存在此字符串");
        }
       
       
       
        //截取字符串
        NSString*nameStr = @"XiaoMing XiaoXue XiaoHong";
        //substringToIndex: 字符串截取,从字符串的开始就一直截取到下标-1减一的位置,包含这个字符
        [nameStr substringToIndex:11];
        NSString*receiveStr = [nameStr substringToIndex:11];
        NSLog(@"receive = %@",receiveStr);
        //根据字符串范围可以得到子字符串下标开始位置nameRange.location
        NSRangenameRang =[nameStr rangeOfString:@"aoH"];
        //给定一个位置,从此位置到最后一个字符串结束
        NSString*XiaoHong = [nameStr substringFromIndex:nameRang.location];
        NSLog(@"XiaoHong = %@",XiaoHong);
       
        //截取字符串任意范围内的子字符串
        //第一种方式
        NSRangeXiaoXue = [nameStr rangeOfString:@"XiaoXue"];
        NSString*XiaoXueStr = [nameStr substringWithRange:XiaoXue];
        NSLog(@"%@",XiaoXueStr);
       
        //第二种方式
        NSString*str9 = [nameStr substringWithRange:NSMakeRange(9, 8)];
        NSLog(@"%@",str9);
       
       
       
        //6.拼接字符串
        NSString*lodStr = [NSStringstringWithFormat:@"I Love You!"];
        //为现有的字符串对象拼接字符串
        NSString*newSrt = [lodStr stringByAppendingString:@"Me Too!"];
        NSLog(@"%@",newSrt);
       
        //拼接格式串
        NSIntegertotalAge = 50;
        NSString*totalStr = [newSrt stringByAppendingFormat:@"%ld",(long) totalAge];
        NSLog(@"%@",totalStr);
       
        //7.替换字符串
        NSString*replaceStr = @"XiaoFeng XiaoAn";
        //将XiaoYu换成XiaoAn,整体替换,前面为被替换内容,后面是将要替换的内容,即用后面的替换前面的
        NSString*newString = [replaceStr stringByReplacingOccurrencesOfString:@"XiaoAn"withString:@"XiaoYu"];
        NSLog(@"%@",newString);
       
        //在某个范围内整体替换
        NSString*twoNewStr = [newString stringByReplacingCharactersInRange:NSMakeRange(4, 9)withString:@"Jin"];
        NSLog(@"%@",twoNewStr);
       
        //8.比较字符串
        NSString*comStr1 = @"Hello!";
        NSString*comSrt2 = @"Hi!";
        NSComparisonResultresult = [comStr1 compare:comSrt2];
        switch(result){
            caseNSOrderedSame:
                NSLog(@"两个字符串相等");
                break;
            caseNSOrderedAscending:
                NSLog(@"前一个字符串比第二个字符串小");
                break;
            caseNSOrderedDescending:
                NSLog(@"前一个字符串比第二个字符串大");
                break;
            default:
                break;

        }
       
        //9.字符串与数值类型转换
        NSString*numberStr = @"123";//若想数值提取成功,则字符串对象里面必须只能出现数字
        //转换为数值类型
        int number = [numberStr intValue];
        printf("number = %d\n",number);
        //转换为float类型
        NSString*floatStr = @"9.8";
        float f = [floatStr floatValue];
        printf("f = %.2f\n",f);
       
       
        //10.大小写转换
        NSString*wordStr = @"Tonight I Close To You";
        //全部转换成大写
        NSString*upperStr = [wordStr uppercaseString];
        NSLog(@"%@",upperStr);
        //全部转换成小写
        NSString*lowStr = [upperStr lowercaseString];
        NSLog(@"%@",lowStr);
        //将单词的首字母大写
        NSString*capitalStr = [lowStr capitalizedString];
        NSLog(@"%@",capitalStr);
       
        //可变字符串NSMutableString 是 NSString 的子类
        //在不可变NSString字符串的基础上,增加了自己独有的一些方法,比如:增删改查
        //创建一个可变字符串对象
        NSMutableString*mutStr = [[NSMutableStringalloc]initWithCapacity:1];
        //使用变量构造器创建
        NSMutableString*mutStr = [NSMutableStringstringWithCapacity:1];
        //拼接字符串
        [mutStr appendFormat:@"NSMutableString!"];
        NSLog(@"%@",mutStr);
        //插入字符串
        [mutStr insertString:@"逗比"atIndex:2];
        NSLog(@"%@",mutStr);
        //删除指定范围的字符串
        //第一种方法
        NSRangerangDelete = [mutStr rangeOfString:@"逗比"];
        [mutStr deleteCharactersInRange:rangDelete];
        NSLog(@"%@",mutStr);
        //第二种方法
        [mutStr deleteCharactersInRange:NSMakeRange(3, 3)];
        NSLog(@"%@",mutStr);
       
       
    }
    return 0;

}