NSPredicate 謂詞

時間 2019-12-08

標籤 nspredicate 謂詞简体版

原文原文鏈接

NSPredicate

簡述：Cocoa框架中的NSPredicate用於查詢，原理和用法都相似於SQL中的where，做用至關於數據庫的過濾取。html

//謂詞
NSPredicate *ca = [NSPredicate predicateWithFormat:(NSString *), ...];

Format：

(1)比較運算符 >,<,==,>=,<=,!= 可用於數值及字符串正則表達式
```
@"number > 100"
```

(2)範圍運算符：IN、BETWEEN數據庫

@"number BETWEEN {1,5}" 
  @"address IN {'shanghai','beijing'}"

(3)字符串自己:SELF框架

@「SELF == ‘APPLE’"函數

(4)字符串相關：BEGINSWITH、ENDSWITH、CONTAINSfetch

@"name CONTAIN[cd] 'ang'"       //包含某個字符串
@"name BEGINSWITH[c] 'sh'"      //以某個字符串開頭
@"name ENDSWITH[d] 'ang'"       //以某個字符串結束
注:[c]不區分大小寫[d]不區分發音符號即沒有重音符號[cd]既不區分大小寫，也不區分發音符號。

(5)通配符：LIKElua

@"name LIKE[cd] '*er*'"    //*表明通配符,Like也接受[cd].
@"name LIKE[cd] '???er*'"

(6)正則表達式：MATCHESurl

NSString *regex = @"^A.+e$";   //以A開頭，e結尾
@"name MATCHES %@",regex

實際應用：

(1)對NSArray進行過濾code

NSArray *array = [[NSArray alloc]initWithObjects:@"beijing",@"shanghai",@"guangzou",@"wuhan", nil];    
NSString *string = @"ang";    
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF CONTAINS %@",string];    
NSLog(@"%@",[array filteredArrayUsingPredicate:pred]);

(2)判斷字符串首字母是否爲字母:orm

NSString *regex = @"[A-Za-z]+";    
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];    

if ([predicate evaluateWithObject:aString]) {    
}

(3)字符串替換：

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:%@",sample);    
NSString* result = [regex stringByReplacingMatchesInString:sample    
                                                      options:0    
                                                       range:NSMakeRange(0, sample.length)    
                                                      withTemplate:@"$1utf-8$2"];    
NSLog(@"Result:%@", result);

(4)截取字符串以下：

//組裝一個字符串，須要把裏面的網址解析出來    
NSString *urlString=@"<meta/><link/><title>1Q84 BOOK1</title></head><body>";    

//NSRegularExpression類裏面調用表達的方法須要傳遞一個NSError的參數。下面定義一個      
NSError *error;    

//http+:[^\\s]* 這個表達式是檢測一個網址的。(?<=title\>).*(?=</title)截取html文章中的<title></title>中內文字的正則表達式    
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(?<=title\\>).*(?=</title)" 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];    

        //從urlString當中截取數據    
        NSString *result=[urlString substringWithRange:resultRange];    
        //輸出結果    
        NSLog(@"->%@<-",result);    
    }    

}

(5)判斷手機號碼，電話號碼函數

// 正則判斷手機號碼地址格式  
- (BOOL)isMobileNumber:(NSString *)mobileNum  
{  
       /** 
        * 手機號碼 
        * 移動：134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188 
        * 聯通：130,131,132,152,155,156,185,186 
        * 電信：133,1349,153,180,189 
        */  
       NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";  
       /** 
        10         * 中國移動：China Mobile 
        11         * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188 
        12         */  
       NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";  
       /** 
        15         * 中國聯通：China Unicom 
        16         * 130,131,132,152,155,156,185,186 
        17         */  
       NSString * CU = @"^1(3[0-2]|5[256]|8[56])\\d{8}$";  
       /** 
        20         * 中國電信：China Telecom 
        21         * 133,1349,153,180,189 
        22         */  
       NSString * CT = @"^1((33|53|8[09])[0-9]|349)\\d{7}$";  
       /** 
        25         * 大陸地區固話及小靈通 
        26         * 區號：010,020,021,022,023,024,025,027,028,029 
        27         * 號碼：七位或八位 
        28         */  
      // NSString * PHS = @"^0(10|2[0-5789]|\\d{3})\\d{7,8}$";  

     NSPredicate *regextestmobile = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", MOBILE];  
     NSPredicate *regextestcm = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CM];  
     NSPredicate *regextestcu = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CU];  
     NSPredicate *regextestct = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CT];  

    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] == YES) {  
          NSLog(@"China Telecom");  
        } else if ([regextestcu evaluateWithObject:mobileNum] == YES) {  
          NSLog(@"China Unicom");  
        } else {  
          NSLog(@"Unknow");  
        }  

        return YES;  
    }  
    else   
    {  
        return NO;  
    }  
}

(6)郵箱驗證、電話號碼驗證:

//是不是有效的正則表達式  

+(BOOL)isValidateRegularExpression:(NSString *)strDestination byExpression:(NSString *)strExpression  

{  

   NSPredicate *predicate = [NSPredicatepredicateWithFormat:@"SELF MATCHES %@", strExpression];    

   return [predicate evaluateWithObject:strDestination];  

}  

//驗證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];  

   return rt;  

}  

//驗證電話號碼  
+(BOOL)isValidateTelNumber:(NSString *)number {  

   NSString *strRegex = @"[0-9]{1,20}";  

   BOOL rt = [CommonTools isValidateRegularExpression:number byExpression:strRegex];  

   return rt;  

}

(7)NSDate進行篩選

//日期在十天以內:  
NSDate *endDate = [[NSDate date] retain];  
NSTimeInterval timeInterval= [endDate timeIntervalSinceReferenceDate];  
timeInterval -=3600*24*10;  
NSDate *beginDate = [[NSDate dateWithTimeIntervalSinceReferenceDate:timeInterval] retain];  
//對coredata進行篩選(假設有fetchRequest)  
NSPredicate *predicate_date =  
[NSPredicate predicateWithFormat:@"date >= %@ AND date <= %@", beginDate,endDate];  

[fetchRequest setPredicate:predicate_date];  
//釋放retained的對象  
[endDate release];  
[beginDate release];

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