NSString的操作,下面记录下他的常用方法:
NSString *str = @"1111111111aaaaaaaaa2222222222";
1、查找
//查找
NSRange range = [str rangeOfString:@"aaa"];
if (range.location == NSNotFound) {
NSLog(@"str中没有找到aaa");
}else{
NSLog(@"str中包含");
}
//另一种方法
if (range.length == ) {
NSLog(@"str中没有找到aaa");
}else{
NSLog(@"str中包含");
}
比较的方法:
[value compare:(NSString *)]; [value compare:(NSString *) options:(NSStringCompareOptions)]; [value compare:(NSString *) options:(NSStringCompareOptions) range:(NSRange)];
这里说下options属性,这个是个枚举,如下:
enum{ NSCaseInsensitiveSearch = ,//不区分大小写比较 NSLiteralSearch = ,//区分大小写比较 NSBackwardsSearch = ,//从字符串末尾开始搜索 NSAnchoredSearch = ,//搜索限制范围的字符串 NSNumbericSearch = //按照字符串里的数字为依据,算出顺序。例如 Foo2.txt < Foo7.txt < Foo25.txt //以下定义高于 mac os 10.5 或者高于 iphone 2.0 可用 NSDiacriticInsensitiveSearch = ,//忽略 "-" 符号的比较 NSWidthInsensitiveSearch = ,//忽略字符串的长度,比较出结果 NSForcedOrderingSearch = //忽略不区分大小写比较的选项,并强制返回 NSOrderedAscending 或者 NSOrderedDescending //以下定义高于 iphone 3.2 可用
NSRegularExpressionSearch = //只能应用于 rangeOfString:..., stringByReplacingOccurrencesOfString:...和 replaceOccurrencesOfString:... 方法。使用通用兼容的比较方法,如果设置此项,可以去掉 NSCaseInsensitiveSearch 和 NSAnchoredSearch }
返回值:
返回值: typedef enum _NSComparisonResult {
NSOrderedAscending = -, // < 升序
NSOrderedSame, // = 等于
NSOrderedDescending // > 降序
} NSComparisonResult;
使用如下:
BOOL result;
result = [str compare:@""];
[str compare:@"" options:NSCaseInsensitiveSearch];
[str compare:@"" options:NSLiteralSearch range:range];
2、截取操作
//截取字符串
//截取,loc标示第几个字符开始,len标示截取两个字符
NSString *bStr = [str substringWithRange:NSMakeRange(, )];
NSLog(@"%@",bStr);
//从第n+1为开始截取,至字符串最后
NSString *bStr1 = [str substringFromIndex:];
NSLog(@"%@",bStr1);
//从首字母开始截取第n个字符
NSString *bStr2 = [str substringToIndex:];
NSLog(@"%@",bStr2);
3、拆分
//拆分
//从字符串8中分割成2个元素的数组 这个方法可以实现字符串和数组直接互转
NSArray *array = [str componentsSeparatedByString:@""];
NSLog(@"array:%@",array);
NSLog(@"ary1 is %@",[array firstObject]);
NSLog(@"ary2 is %@",[array lastObject]);
4、替换
NSString *str1 = @"";
NSString *replacedStr = [str1 stringByReplacingOccurrencesOfString:@"" withString:@"想要替换成字符串"];
NSLog(@"erplacedStr === %@",replacedStr);
5、插入
//插入 只能对可变字符串操作,下面insert方法,依次是原字符串,插入的字符,插入的位置
NSMutableString *currentStr = [NSMutableString stringWithFormat:@"%@",@"豫A88888"];
NSMutableString *insertStr = [[NSMutableString alloc]initWithString:@"-"];
[currentStr insertString:insertStr atIndex:];
NSLog(@"currentstr is %@",currentStr);
6、验证
//验证,包含的前标和后标
NSString *str2 = @"http:www.baidu.com";
BOOL a = [str2 hasPrefix:@"http"];//前缀
BOOL b = [str2 hasSuffix:@"com"];//后缀
NSLog(@"a===%@,b===%@",a ?@"YES":@"NO",b ?@"YES":@"NO");
7、大小写互转
//改变字符串的大小写
NSString *str3 = @"zhengXZHOU";
NSString *da = [str3 uppercaseString];//转成大写
NSString *xiao = [str3 lowercaseString];//转成小写
NSString *shouDa = [str3 capitalizedString];//首字母大写,其余小写
NSLog(@"\n%@\n%@\n%@",da,xiao,shouDa);
8、编码 解码
//编码 解码
//编码
NSString *hStr = @"你好啊";
NSString *uniStr = [NSString stringWithUTF8String:[hStr UTF8String]];
NSData *uniData = [uniStr dataUsingEncoding:NSNonLossyASCIIStringEncoding];
NSString *goodStr = [[NSString alloc] initWithData:uniData encoding:NSUTF8StringEncoding] ;
NSLog(@"goodstr is %@",goodStr); //解码
const char *jsonstr = [goodStr UTF8String];
NSData *jsonData = [NSData dataWithBytes:jsonstr length:strlen(jsonstr)];
NSString *goodMsg = [[NSString alloc]initWithData:jsonData encoding:NSNonLossyASCIIStringEncoding];
NSLog(@"goodmsg is %@",goodMsg);
下面附上相应的打印:
仅做记录!