获取字符串中的空白后的字符在iOS中

Question

我有这样一个字符串：@"The Happy Day"，我想只在另一个字符串中保存"THD"。我怎样才能做到这一点？

Answer 1

我会做这样的...

NSString *string = @"The Happy Day"; 

// Create array of words in string... 
NSArray *words = [string componentsSeparatedByString:@" "]; 

// Create array to hold first letter of each word... 
NSMutableArray *firstLetters = [NSMutableArray arrayWithCapacity:[words count]]; 

// Iterate through words and add first letter of each word to firstLetters array... 
for (NSString *word in words) { 
    if ([word length] == 0) continue; 
    [firstLetters addObject:[word substringToIndex:1]]; 
} 

// Join the first letter error into a single string... 
NSString *acronym = [firstLetters componentsJoinedByString:@""]; 

它可以使用雨燕的功能类型，如map做要好得多，但也有不一样，在任何目的内置方法-C。

Answer 2

NSString *str = @"The Happy Day"; 

NSMutableString *result = [NSMutableString string]; 
[[str componentsSeparatedByString:@" "] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) { 
     if(obj){ 
      [result appendString:[((NSString *)obj) substringToIndex:1]]; 
     } 

}];