“This is the 23rd day of my participation in the First Challenge 2022. For details: First Challenge 2022.”

The introduction

Use NSPredicate to search for elements of a particular condition from an array:

  1. Filter the selected specification data
  2. Regroups an array of objects with date attributes by date
  3. Urban search
  4. Concatenation of multiple filter criteria: filtering of bank lists
  5. Filtering of string arrays (array elements are of system type)
  6. Data query for Core Data
  7. Grouping data using predicates (array elements are of custom type)

Use regular expressions to match lookup data:

  1. Use regular expressions to monitor keywords in chat logs
  2. Application of NSPredicate in regular expressions: regular expressions that limit UITextField to input only amount (0.. 00)

Use system-specific apis for data lookups to avoid looping through sets of numbers:

  1. Use NSPredicate to filter the electronic signature data of type=8 from the array to avoid traversing the set of certificateInfoList
  2. Use makeObjectsPerformSelector to avoid loop array
  3. Use the method starting with enumerate

I searches an array for elements of a particular condition

  • Search for conditional elements from arrays (Filter e-signature data from arrays with Type =8, avoid traversing sets of certificateInfoList)
  • Kunnan.blog.csdn.net/article/det…

II Application of regular expressions

  • IOS data search skills [regular expression application]

Kunnan.blog.csdn.net/article/det…

III. Avoid looping over a number set

3.1 use NSPredicate to filter the e-signature data of type=8 from the array and avoid going through the set of certificateInfoList

  • Find e-signature data [avoid traversing sets of certificateInfoList, determine type=8]

Blog.csdn.net/z929118967/…

- (CRMcertificateInfoListDto *)getSignimgURLCRMcertificateInfoListDto{
    

    NSPredicate* predicate = [NSPredicate predicateWithFormat:@"type == %@"The [[NSNumber numberWithInteger:CRMcertificateInfoListDtotype4Sign] description]];
    
    
    

    NSArray *arFiltered = [  self.certificateInfoList filteredArrayUsingPredicate:predicate];// Filter the maTemp array with a certain criteria (specific date), i.e., do a big data search.
    CRMcertificateInfoListDto *dto = nil;
    
    
    if(arFiltered.count>0){
        
        dto =  arFiltered.firstObject;
        

    }
    
    
    return dto;

}

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3.2 use makeObjectsPerformSelector to avoid loop array

  • Using makeObjectsPerformSelector set self. StorePayFeeRateListDto. The attribute of internal elements settlementCycle payFeeRateList array (settlement cycle: 0-T0 1-T1 default 0) to avoid looping convenience arrays
    [self.StorePayFeeRateListDto.payFeeRateList makeObjectsPerformSelector:@selector(setSettlementCycle:) withObject:swichStr];

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  • Loop through the code of the array
        for (int i = 0; i < self.StorePayFeeRateListDto.payFeeRateList.count; i++) {//settlementCycle
            
            
            
            NSMutableDictionary * mutDic = [[NSMutableDictionary alloc]initWithDictionary:_sectionArr[i]];
            
            
            
            
            [mutDic setObject:swichStr forKey:@"settlementCycle"];
            
            
            [_sectionArr setObject:mutDic atIndexedSubscript:i];
            
            
            
            
        }
    

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3.3 Using the method starting with Enumerate

[objc] view plain copy
/* In the enumerate methods, the blocks will be invoked inside an autorelease pool, so any values assigned inside the block should be retained. */  
- (void)enumerateSubstringsInRange:(NSRange)range options:(NSStringEnumerationOptions)opts usingBlock:(void(^) (NSString * __nullable substring, NSRange substringRange, NSRange enclosingRange, BOOLBOOL *stop))block NS_AVAILABLE(10_6, 4_0);  
- (void)enumerateLinesUsingBlock:(void(^) (NSString *line, BOOLBOOL *stop))block NS_AVAILABLE(10_6, 4_0);  

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  • Used to read the contents of a TXT document line by line
    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"girl" ofType:@"txt"];  
    NSData *fileData = [NSData dataWithContentsOfFile:filePath];  
    NSString *fileStr = [[NSString alloc]initWithData:fileData encoding:NSUTF8StringEncoding];  
      
    // Read line by line
    [fileStr enumerateLinesUsingBlock:^(NSString * _Nonnull line, BOOLBOOL * _Nonnull stop) {  
        NSLog(@"%@\n",line);  
    }];  
      
// read character by character
    [fileStr enumerateSubstringsInRange:NSMakeRange(0, fileStr.length) options:NSStringEnumerationByWords usingBlock:^(NSString * _Nullable substring, NSRange substringRange, NSRange enclosingRange, BOOLBOOL * _Nonnull stop) {  
        NSLog(@"tmp111===%@",substring);  
    }];  

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  • An example of traversing a payment password
  // read character by character
    [fileStr enumerateSubstringsInRange:NSMakeRange(0, fileStr.length) options:NSStringEnumerationByComposedCharacterSequences
                             usingBlock:^(NSString * _Nullable substring, NSRange substringRange, NSRange enclosingRange, BOOL * _Nonnull stop) {
                                 
                             

        
        NSLog(@"tmp111===%@",substring);
        
        [m_textField appendPsw:substring];
        [_pswView SetInputNum:_inputEncData.count];
        [m_textField onChange];
        
    }];
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  • NSStringEnumerationByWords
    [fileStr enumerateSubstringsInRange:NSMakeRange(0, fileStr.length) options:NSStringEnumerationByWords
                             usingBlock:^(NSString * _Nullable substring, NSRange substringRange, NSRange enclosingRange, BOOL * _Nonnull stop) {
                                 
                             

        
        NSLog(@"tmp111===%@",substring);
        
        [m_textField appendPsw:substring];
        [_pswView SetInputNum:_inputEncData.count];
        [m_textField onChange];
        
    }];
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see also

1. Please input the correct settlement card number [Luhn algorithm of bank Card Number validity verification] – Bank card number verification algorithm 2. Id card verification: [Verification age and whether verification meets the rules of ID card number generation]

Blog.csdn.net/z929118967/…

BOOL in OC is not as good as BOOL

BOOL means 1 is YES, so non-1 is NO. BOOL means 0 is false, so non-0 is true;

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