IOS NSPredicate 及正则表达式

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一、Predicate

Predicate译为断言。

官网：Predicates wrap some combination of expressions and operators and when evaluated return a BOOL.

常用方法:

+ (NSPredicate *)predicateWithFormat:(NSString *)predicateFormat, ...;

常用Format：

(1)比较运算符>,<,==,>=,<=,!=
可用于数值及字符串
例：@"num > 100"
(2)范围运算符：IN、BETWEEN
例：@"num BETWEEN {1,5}"
@"addr IN {'shanghai','beijing'}"

(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。
注：CONTAIN 只能判断是否包含特定字符，而非正则表达式

(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

示例：

    NSString *wordReg = @"^[a-zA-Z0-9]\\w{5,15}$";        NSString *digitalReg = @"1";    NSString *lettersReg = @"a";        NSPredicate *wordPre = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",wordReg];    NSPredicate *digitalPre = [NSPredicate predicateWithFormat:@"SELF CONTAINS %@", digitalReg];    NSPredicate *lettersPre = [NSPredicate predicateWithFormat:@"SELF CONTAINS %@",lettersReg];        MPLog(@"word:%d     digital:%d       letters:%d",[wordPre evaluateWithObject:text],[digitalPre evaluateWithObject:text],[lettersPre evaluateWithObject:text]);    if ([digitalPre evaluateWithObject:text] == YES&&[lettersPre evaluateWithObject:text]==YES&&[wordPre evaluateWithObject:text]==YES)        return YES;    else        return NO;

二、正则 NSRegularExpression

- (NSTextCheckingResult *)firstMatchInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range;

示例：

    NSString *urlString = @"sfdshttp://www.baidu.com";    NSError *error;    //http+:[^\\s]* 这是检测网址的正则表达式    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"http+:[^\\s]*" options:0 error:&error];        if (regex != nil) {        NSTextCheckingResult *firstMatch = [regex firstMatchInString:urlString options:0 range:NSMakeRange(0, [urlString length])];                if (firstMatch) {            NSRange resultRange = [firstMatch rangeAtIndex:0];            //从urlString中截取数据                        NSString *result = [urlString substringWithRange:resultRange];            MPLog(@"%@",result);        }    }            NSRegularExpression *wordReg = [NSRegularExpression regularExpressionWithPattern:@"^[a-zA-Z0-9]\\w{5,15}$" options:0 error:&error];        NSRegularExpression *digitalReg = [NSRegularExpression regularExpressionWithPattern:@"[a-zA-Z]" options:0 error:&error];    NSRegularExpression *lettersReg = [NSRegularExpression regularExpressionWithPattern:@"[0-9]" options:0 error:&error];            NSTextCheckingResult *result1 = [wordReg firstMatchInString:text options:0 range:NSMakeRange(0, text.length)];    NSTextCheckingResult *result2 = [digitalReg firstMatchInString:text options:0 range:NSMakeRange(0, text.length)];    NSTextCheckingResult *result3 = [lettersReg firstMatchInString:text options:0 range:NSMakeRange(0, text.length)];        MPLog(@"wordReg:%d  digitalReg:%d    lettersReg:%d",[result1 rangeAtIndex:0].length,[result2 rangeAtIndex:0].length,[result3 rangeAtIndex:0].length);        if ([result1 rangeAtIndex:0].length>0&&[result2 rangeAtIndex:0].length>0&&[result3 rangeAtIndex:0].length) {        return YES;    }else {        return NO;    }

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