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POParsing CSV: how can NSScanner recognize empty field (i.e. ,,)?
 

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  1. POParsing CSV: how can NSScanner recognize empty field (i.e. ,,)?
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    <p>I am very new to Xcode and trying - as millions - to parse a CSV file. I have read many contributions and I am managing it but I have a problem when my NSScanner intercepts an empty field: "Field_A, Field_B,, Field_D". I guess it is because it ignores empty space by default, or in this case no space at all.</p> <p>String is:</p> <p>"Personal","2011-01-01","Personal","Cigarettes",,4.60,"Cash","",</p> <p>I tried to debug it using scanLocation:</p> <pre><code>2011-04-22 15:57:32.414 Spending[42015:a0f] Before while...scan location is:0 2011-04-22 15:57:32.414 Spending[42015:a0f] Account: "Personal" - scan location is:10 2011-04-22 15:57:32.415 Spending[42015:a0f] Date: "2011-01-01" - scan location is:23 2011-04-22 15:57:32.415 Spending[42015:a0f] Category: "Personal" - scan location is:34 2011-04-22 15:57:32.416 Spending[42015:a0f] Subcategory: "Cigarettes" - scan location is:47 2011-04-22 15:57:32.416 Spending[42015:a0f] Income: 4.600000 - scan location is:53 2011-04-22 15:57:32.416 Spending[42015:a0f] Expense: 0.000000 - scan location is:53 2011-04-22 15:57:32.417 Spending[42015:a0f] Payment: "Cash" - scan location is:60 2011-04-22 15:57:32.417 Spending[42015:a0f] Note: "" - scan location is:63 </code></pre> <p>And as you can see after that even expense field gets no value (should be 4.60).</p> <p>Here is the relevant piece of code:</p> <pre><code>NSScanner *scanner = [NSScanner scannerWithString:fileString]; [scanner setCharactersToBeSkipped: [NSCharacterSet characterSetWithCharactersInString:@"\n, "]]; NSString *account, *date, *category, *subcategory, *payment, *note; float income, expense; // Set up data delimiter using comma NSCharacterSet *commaSet; commaSet = [NSCharacterSet characterSetWithCharactersInString:@","]; NSLog (@"Before while...scan location is:%d\n", scanner.scanLocation); [scanner scanUpToCharactersFromSet:commaSet intoString:&amp;account]; NSLog(@"Account: %@ - scan location is:%d\n",account, scanner.scanLocation); [scanner scanUpToCharactersFromSet:commaSet intoString:&amp;date]; NSLog(@"Date: %@ - scan location is:%d\n",date, scanner.scanLocation); [scanner scanUpToCharactersFromSet:commaSet intoString:&amp;category]; NSLog(@"Category: %@ - scan location is:%d\n",category, scanner.scanLocation); [scanner scanUpToCharactersFromSet:commaSet intoString:&amp;subcategory]; NSLog(@"Subcategory: %@ - scan location is:%d\n",subcategory, scanner.scanLocation); [scanner scanFloat:&amp;income]; NSLog(@"Income: %f - scan location is:%d\n",income, scanner.scanLocation); [scanner scanFloat:&amp;expense]; NSLog(@"Expense: %f - scan location is:%d\n",expense, scanner.scanLocation); [scanner scanUpToCharactersFromSet:commaSet intoString:&amp;payment]; NSLog(@"Payment: %@ - scan location is:%d\n",payment, scanner.scanLocation); [scanner scanUpToCharactersFromSet:commaSet intoString:&amp;note]; NSLog(@"Note: %@\n - scan location is:%d",note, scanner.scanLocation); </code></pre> <p>I tried looking carefully through NSScanner Class Reference, but could not get an idea? Do you have any? </p> <p>Thanks, Fabrizio.</p>
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    1. USFabrizio Prosperi
    1. USFabrizio Prosperi
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      1. POParsing CSV: how can NSScanner recognize empty field (i.e. ,,)?
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    1. COAt least fix the NSLogs to show `income` and `expense` instead of `&income` and `&expense`.
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    2. COYes, you are right, changing the post now!
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      1. USFabrizio Prosperi
 

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