NSString的使用

#pragma mark - 2、字符串的常用功能
-(void)commonFunction{
    //1、追加字符串
    NSString * str = @"Hello";
    NSString * book = @",book";
    NSString * strBook = [str stringByAppendingString:book];
    NSLog(@"str = %@",str);
    NSLog(@"strBook = %@",strBook);
    
    //2、追加带变量的字符串
    NSString * fStr = @"Hello";
    NSString * formatStr = [fStr stringByAppendingFormat:@",%@Book",@"Good"];
    NSLog(@"fStr = %@",fStr);
    NSLog(@"formatStr = %@",formatStr);
    
    //3、字符串的截取
    NSString * string = @"hello,this is a good book";
    NSString * subStr1 = [string substringToIndex:10];//0-10的子字符串
    NSString * subStr2 = [string substringFromIndex:10];//10-末尾的子字符串
    NSString * subStr3 = [string substringWithRange:NSMakeRange(2, 3)];//2开始的3个字符长度的字符串
    NSLog(@"subStr1 = %@",subStr1);
    NSLog(@"subStr2 = %@",subStr2);
    NSLog(@"subStr3 = %@",subStr3);
    
    //4、子字符串所在位置及长度
    NSString * mainString = @"hello,world";
    NSString * subStr = @"world";
    NSRange range = [mainString rangeOfString:subStr];
    NSLog(@"range.location = %ld,range,length = %ld",range.location,range.length);
    
    //5、字符串统一转大小写
    NSString * smallBigStr = @"Hello,World";
    NSString * smallStr = [smallBigStr lowercaseString];
    NSString * bigStr = [smallBigStr uppercaseString];
    NSLog(@"smallStr = %@",smallStr);
    NSLog(@"bigStr = %@",bigStr);
    
    //6、字符串前后缀
    NSString * preString = @"hello,world";
    BOOL hasPre = [preString hasPrefix:@"hello"];
    NSLog(@"hasPre = %d",hasPre);
    NSString * sufString = @"hello,world";
    [sufString hasSuffix:@"world"];
    NSLog(@"sufString = %d",hasPre);
    
    //7、字符串长度
    NSString * lengthStr = @"hello,world";
    NSLog(@"lengthStr.length = %ld",lengthStr.length);
    
    //8、字符串中的字符
    NSString * charStr = @"hello,world";
    unichar c = [charStr characterAtIndex:0];
    NSLog(@"c = %c",c);
    
    //9、字符串的比较
    NSString * compareStr1 = @"hello";
    NSString * compareStr2 = @"world";
    NSComparisonResult result = [compareStr1 compare:compareStr2];
    NSLog(@"result = %d",result);
    
    BOOL isEqual = [compareStr1 isEqualToString:compareStr2];
    NSLog(@"isEqual = %d",isEqual);
    
    //10、字符串的分割
    NSString * sepStr = @"hello-world";
    NSArray * setArray = [sepStr componentsSeparatedByString:@"-"];
    NSLog(@"setArray = %@",setArray);
    
    NSCharacterSet * charSet = [NSCharacterSet characterSetWithCharactersInString:@"-o"];
    NSArray * array = [sepStr componentsSeparatedByCharactersInSet:charSet];
    NSLog(@"array = %@",array);
}
 
 

#pragma mark - 3、可变字符串
-(void)mutableStringFun{
    NSMutableString * mString = [[NSMutableString alloc] initWithString:@"hello"];
    //1、追加字符串
    [mString appendString:@",book"];
    NSLog(@"mString = %@",mString);
    
    //2、追加带变量的字符串
    [mString appendFormat:@".%@ Good Book",@"This Is A"];
    NSLog(@"mString = %@",mString);
    
    //3、删除指定位置字符
    [mString deleteCharactersInRange:NSMakeRange(0, 6)];
    NSLog(@"mString = %@",mString);
    
    //4、替换指定位置字符
    [mString replaceCharactersInRange:NSMakeRange(0, 6) withString:@"你好"];
    NSLog(@"mString = %@",mString);
    
    //5、在指定位置插入字符
    [mString insertString:@"你好" atIndex:7];
    NSLog(@"mString = %@",mString);
    
    //6、覆盖字符串
    [mString setString:@"你好，世界"];
    NSLog(@"mString = %@",mString);
    
   
}

#pragma mark - 4、其它方法
//将int类型 转为16进制的字符串1
-(void)hexStringFromNum{
    int num = 16;
    NSString *hexString = [NSString stringWithFormat:@"%@",[[NSString alloc] initWithFormat:@"%1x",num]];
    NSLog(@"hexString = %@",hexString);
}
 
//将int类型 转为16进制的字符串2(待验证)
-(void)longlongToHexStr{
    NSInteger value = 16;
    int len = 2;
    char ASSICCHAR[] = "0123456789ABCDEF";;
    char resultBuffer[len];
    for (int i = 0; i < len; i++) {
        resultBuffer[len - i - 1] = ASSICCHAR[(value >> (i * 4)) & 0x0F];
    }
    NSString * hexString = [NSString stringWithCString:resultBuffer encoding:NSASCIIStringEncoding];
    NSLog(@"hexString = %@",hexString);
}
 
//字典转为json格式字符串
-(NSString*)jsonStringFromDict{
    NSDictionary * dict = @{@"1":@"test1",
                            @"2":@"test3"};
    NSData * mData = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:nil];
    NSString * dictString = [[NSString alloc] initWithData:mData encoding:NSUTF8StringEncoding];
    NSLog(@"dictString = %@",dictString);
    return dictString;
}
 
//将json格式字符串转为字典
-(NSDictionary *)parseJSONStringToNSDictionary{
    NSString * JSONString = [self jsonStringFromDict];
    //将字符串转成二进制数据
    NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
    //利用系统自带的JSON解析，解析成字典格式
    NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
    //将字典返回
    NSLog(@"responseJSON = %@",responseJSON);
    return responseJSON;
}
 
//去掉非数字字符
-(void)removeUnnumberChar{
    NSString * number = @"156-8888-8888";
    //invertedset:为翻转
    NSCharacterSet *setToRemove = [[ NSCharacterSet characterSetWithCharactersInString:@"0123456789"] invertedSet];
    NSArray * numArray = [number componentsSeparatedByCharactersInSet:setToRemove];
    NSLog(@"numArray = %@",numArray);
    NSString *phoneStr = [numArray componentsJoinedByString:@""];
 
}

//字符串与int类型互转
-(void)stringToInt{
    
    //数字转字符串
    int num = 12;
    NSString * intString = [NSString stringWithFormat:@"%d",num];
    NSLog(@"intString = %@",intString);
    
    //字符串转数字
    NSString * string = @"12";//会转为12；类似@”我“这样的非数字的字符串会转为0
    NSInteger stringInt = [string integerValue];
    NSLog(@"stringInt = %ld",stringInt);
 
}

//字符串与data互转
-(void)stringToData{
    //把字符串再转变为二进制流
    NSString * string = @"I have a dream";
    NSData * data=[NSMutableData dataWithData:[string dataUsingEncoding:NSUTF8StringEncoding]];
    NSLog(@"data = %@",data);
    
    //二进制流转变为字符串
    NSString * dataStr=[[NSMutableString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"dataStr = %@",dataStr);
 
}