学习ios之二NSStringNSNumber

//-------------------        NSNumber
        //创建一个NSNumber
        NSNumber * monthNumber=[NSNumber numberWithInt:10];
        NSNumber * lengthNumber=[[NSNumber alloc]initWithFloat:10.8];
        NSLog(@"monthNumber:%@",monthNumber);
        NSLog(@"lengthNumber:%@",lengthNumber);
        
        
        //还原成基本类型
        int month=[monthNumber intValue];
        float length=[lengthNumber floatValue];
        NSLog(@"month:%d",month);
        NSLog(@"length:%1f",length);
        
        //-------------------        NSString
        
        //创建空字符串
        NSString * string1=@"这是一个字符串常量";
        NSString * string2=[[NSString alloc]init];
        NSString * string3=[NSString string];
        
        NSLog(@"string1 %@",string1);

        NSLog(@"string2 %@",string2);

        NSLog(@"string3 %@",string3);

        //常量区
        NSString * string4=[[NSString alloc]initWithString:@"abc"];
        NSString * string5=[NSString stringWithString:string4];
        
        NSLog(@"string4 %@",string4);
        NSLog(@"string5 %@",string5);
        
        //堆区
        NSString * string6=[[NSString alloc]initWithFormat:@"%d",10];
        NSString *string7=[NSString stringWithFormat:@"%f",10.8];
        
        NSLog(@"string6 %@",string6);
        NSLog(@"string7 %@",string7);

        //内容是否相同
        if ([string4 isEqualToString:string5]) {
            NSLog(@"same");
        }
        else{
            NSLog(@"different");
        }
        
        //同一个对象
        if (string1==string2) {
            NSLog(@"y");
        }
        
        //比较字符串大小
        //NSOrderedAscending = -1L, NSOrderedSame, NSOrderedDescending
        NSLog(@"%ld",[string4 caseInsensitiveCompare:string5]);
        
        //字符串长度
         NSLog(@"%ld",[string4 length]);
        
        //改变字符串大小写
        NSString *hello=@"hello WORLD";
        NSLog(@"%@",[hello uppercaseString]);//全部大写
        NSLog(@"%@",[hello lowercaseString]);//   小写
        NSLog(@"%@",[hello capitalizedString]);//首字母大写
        
        //字符串转--基本数据类型
        NSString * string11=@"3.3333";
        NSLog(@"%d",[string11 boolValue]);
        NSLog(@"%f",[string11 floatValue]);
        NSLog(@"%f",[string11 doubleValue]);
        NSLog(@"%d",[string11 intValue]);
        
        //字符串转数组
        NSString * string12=@"abc ddd eee";
        NSArray *array=[string12 componentsSeparatedByString:@" "];
        NSLog(@"%@",array);
        
        //截取字符串
        NSString *string13=[NSString stringWithFormat:@"abcdef"];
        //从字符串的开头一直截取到指定位置，但不包括该位置的字符
        NSString * string14=[string13 substringToIndex:2];//ab
         NSLog(@"string14 %@",string14);
        //以指定位置开始（包括指定位置的字符），并包括之后的全部字符串
        NSString * string15=[string13 substringFromIndex:2];
         NSLog(@"string15 %@",string15);//cedf
        //根据范围截取字符串
        NSRange range={4,2};
//        range.location=4;
//        range.length=2;
        NSString *string16=[string13 substringWithRange:range];
        NSLog(@"string16 %@",string16);//ef
        
        //拼接字符串
        NSString * string17=@"1",*string18=@"2";
        NSString *string19=[[NSString alloc]initWithFormat:@"拼接：%@ and %@",string17,string18];
         NSLog(@"string19 %@",string19);
        NSString* string20=[string17 stringByAppendingFormat:@"%@",string18];
        NSString *string21=[string17 stringByAppendingString:string18];
          NSLog(@"string20 %@",string20);
          NSLog(@"string21 %@",string21);
        
        //查询字符串
        NSString *sting22=@"skjdlfjskldfaaaajsldjfklsjdfsjkajdkf";
        NSRange range11=[sting22 rangeOfString:@"aaaa"];
        if (range11.location!=NSNotFound) {
            NSLog(@"找到");
        }

        
        //可变字符串 继承NSString
        //插入
        NSMutableString *str=[NSMutableString stringWithString:@"skjlfjksljdkf"];
        [str insertString:@"11111" atIndex:0];
        NSLog(@"%@",str);
        //删除
        [str deleteCharactersInRange:NSMakeRange(1,2)];
        NSLog(@"%@",str);
 
        //替换
        [str replaceCharactersInRange:NSMakeRange(0, 2) withString:@"45"];
        NSLog(@"%@",str);