考虑以下示例:

"    Hello      this  is a   long       string!   "

我想把它转换成:

"Hello this is a long string!"

最佳答案

OS X 10.7+ 和 iOS 3.2+

使用原生 regexp solution由 hfossli 提供。

否则

使用您最喜欢的正则表达式库或使用以下 Cocoa-native 解决方案:

NSString *theString = @"    Hello      this  is a   long       string!   ";

NSCharacterSet *whitespaces = [NSCharacterSet whitespaceCharacterSet];
NSPredicate *noEmptyStrings = [NSPredicate predicateWithFormat:@"SELF != ''"];

NSArray *parts = [theString componentsSeparatedByCharactersInSet:whitespaces];
NSArray *filteredArray = [parts filteredArrayUsingPredicate:noEmptyStrings];
theString = [filteredArray componentsJoinedByString:@" "];

https://stackoverflow.com/questions/758212/