NSScanner类参考

 NSString *string = @"Product: Acme Potato Peeler; Cost: 0.98 73\nProduct: Chef Pierre Pasta Fork; Cost: 0.75 19\nProduct: Chef Pierre Colander; Cost: 1.27 2\n";

 NSCharacterSet *semicolonSet;
 NSScanner *theScanner;

 NSString *PRODUCT = @"Product:";
 NSString *COST = @"Cost:";

 NSString *productName;
 float productCost;
 NSInteger productSold;

 semicolonSet = [NSCharacterSet characterSetWithCharactersInString:@";"];
 theScanner = [NSScanner scannerWithString:string];

 while ([theScanner isAtEnd] == NO)
 {
     if ([theScanner scanString:PRODUCT intoString:NULL] &&
         [theScanner scanUpToCharactersFromSet:semicolonSet
             intoString:&productName] &&
         [theScanner scanString:@";" intoString:NULL] &&
         [theScanner scanString:COST intoString:NULL] &&
         [theScanner scanFloat:&productCost] &&
         [theScanner scanInteger:&productSold])
     {
         NSLog(@"Sales of %@: $%1.2f", productName, productCost * productSold);
     }
 }

 

 

 

 

 

Scans the string until a given string is encountered, accumulating characters into a string that’s returned by reference.

(从当前位置开始，根据指定的字符串扫描，直到找到指定的字符串停止（不不会指定的字符串），返回从当前位置开始到指定字符串之间的字符串，并赋值给（stringValue）这个参数)

- (BOOL)scanUpToString:(NSString *)stopString intoString:(NSString **)stringValue

 

 

Scans a given string, returning an equivalent string object by reference if a match is found.

（跳过指定的字符串） stringValue中的值和string 中的一样

- (BOOL)scanString:(NSString *)string intoString:(NSString **)stringValue