转自:http://www.cnblogs.com/thefeelingofsimple/archive/2013/01/31/2886915.html
简述:Cocoa框架中的NSPredicate用于查询,原理和用法都类似于SQL中的where,作用相当于数据库的过滤取。
最常用到的函数
+ (NSPredicate *)predicateWithFormat:(NSString *)predicateFormat,...;
1.比较运算符 > 、< 、== 、 >= 、<= 、 != 例:@"number >= 99"
2.范围运算符:IN 、BETWEEN 例:@"number BETWEEN {1,5}" @"address IN {'shanghai','nanjing'}" 3.字符串本身:SELF 例:@"SELF == 'APPLE'" 4.字符串相关:BEGINSWITH、ENDSWITH、CONTAINS 例:@"name CONTAIN[cd] 'ang'" //包含某个字符串 @"name BEGINSWITH[c] 'sh'" //以某个字符串开头 @"name ENDSWITH[d] 'ang'" //以某个字符串结束 注:[c]不区分大小写,[d]不区分发音符号即没有重音符号,[cd]既不区分大小写,也不区分发音符号。 5.通配符:LIKE 例:@"name LIKE[cd] '*er*'" //*代表通配符,Like也接受[cd]. @"name LIKE[cd] '???er*'"
6.正则表达式:MATCHES 例:NSString *regex = @"^A.+e$"; //以A开头,e结尾 @"name MATCHES %@",regex
实际应用:对NSArray进行过滤
NSArray *array = [[NSArray alloc]initWithObjects:@"beijing",shanghaiguangzouwuhan",nil];
NSString *string = ang;
NSPredicate *pred = [NSPredicate predicateWithFormat:SELF CONTAINS %@string];
NSLog(%@
实际应用:判断字符串首字母是否为字母
NSString *regex = [A-Za-z]+;
NSPredicate *predicate = [NSPredicate predicateWithFormat:SELF MATCHES %@if ([predicate evaluateWithObject:aString]) {
}
实际应用:字符串替换
NSError* error = NULL;
NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:(encoding=")[^"]+(")
options:0
error:&error];
NSString* sample = <xml encoding="abc></xml><xml encoding="def"></xml><xml encoding="ttt"></xml>;
NSLog(Start:%@ [regex stringByReplacingMatchesInString:sample
options:
range:NSMakeRange($1utf-8$2Result:%@
实际应用:截取字符串
//组装一个字符串,需要把里面的网址解析出来
NSString *urlString=<meta/><link/><title>1Q84 BOOK1</title></head><body>;
NSRegularExpression类里面调用表达的方法需要传递一个NSError的参数。下面定义一个
NSError *error;
http+:[^s]* 这个表达式是检测一个网址的。(?<=title&;).*(?=</title)截取html文章中的<title></title>中内文字的正则表达式
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:(?<=title>).*(?=</title)" options:0 error:&error];
if (regex != nil) {
NSTextCheckingResult *firstMatch=[regex firstMatchInString:urlString options:0 range:NSMakeRange( (firstMatch) {
NSRange resultRange = [firstMatch rangeAtIndex:];
从urlString当中截取数据
NSString *result=[urlString substringWithRange:resultRange];
输出结果
NSLog(->%@<-
实际应用:判断手机号码,电话号码函数
正则判断手机号码地址格式
- (BOOL)isMobileNumber:(NSString * )mobileNum
{
/**
* 手机号码
* 移动:134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188
* 联通:130,131,132,152,155,156,185,186
* 电信:133,1349,153,180,189
*/
NSString * MOBILE = ^1(3[0-9]|5[0-35-9]|8[025-9])d{8}$;
*
10 * 中国移动:China Mobile
11 * 134[0-8],188
12
NSString * CM = ^1(34[0-8]|(3[5-9]|5[017-9]|8[278])d)d{7}$*
15 * 中国联通:China Unicom
16 * 130,186
17
NSString * CU = ^1(3[0-2]|5[256]|8[56])d{8}$*
20 * 中国电信:China Telecom
21 * 133,189
22
NSString * CT = ^1((33|53|8[09])[0-9]|349)d{7}$*
25 * 大陆地区固话及小灵通
26 * 区号:010,020,021,022,023,024,025,027,028,029
27 * 号码:七位或八位
28 */
NSString * PHS = @"^0(10|2[0-5789]|d{3})d{7,8}$";
NSPredicate *regextestmobile = [NSPredicate predicateWithFormat: *regextestcu = [NSPredicate predicateWithFormat:if (([regextestmobile evaluateWithObject:mobileNum] == YES)
|| ([regextestcm evaluateWithObject:mobileNum] == YES)
|| ([regextestct evaluateWithObject:mobileNum] == YES)
|| ([regextestcu evaluateWithObject:mobileNum] == YES))
{
if([regextestcm evaluateWithObject:mobileNum] == YES) {
NSLog(China Mobile);
} else if([regextestct evaluateWithObject:mobileNum] ==China Telecomif ([regextestcu evaluateWithObject:mobileNum] ==China Unicomelse {
NSLog(Unknow);
}
return YES;
}
{
NO;
}
}
实际应用:邮箱验证、电话号码验证
是否是有效的正则表达式
+(BOOL)isValidateRegularExpression:(NSString *)strDestination byExpression:(NSString * )strExpression
{
NSPredicate *predicate = [NSPredicatepredicateWithFormat: [predicate evaluateWithObject:strDestination];
}
验证email
+(BOOL)isValidateEmail:(NSString * )email {
NSString *strRegex = [A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+.[A-Za-z]{1,5};
BOOL rt = [CommonTools isValidateRegularExpression:email byExpression:strRegex];
rt;
}
验证电话号码
+(BOOL)isValidateTelNumber:(NSString * )number {
NSString *strRegex = [0-9]{1,20} [CommonTools isValidateRegularExpression:number byExpression:strRegex];
rt;
}
实际应用:NSDate进行筛选
日期在十天之内:
NSDate *endDate = [[NSDate date] retain];
NSTimeInterval timeInterval= [endDate timeIntervalSinceReferenceDate];
timeInterval -= 3600* 24* 10;
NSDate *beginDate = [[NSDate dateWithTimeIntervalSinceReferenceDate:timeInterval] retain];
对coredata进行筛选(假设有fetchRequest)
NSPredicate *predicate_date =
[NSPredicate predicateWithFormat:date >= %@ AND date <= %@释放retained的对象
[endDate release];
[beginDate release];
(编辑:李大同)
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