Objective-C 去掉NSString 前后中空格

NSString 中缺少类似 Java 中的 .trim() 方法。直接去掉字符串类型值前后的空格。需要使用如下方法。

 

1、去掉前后空格

NSString *cleanString = [dirtyString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; 

2、还有就是去除多于的空格，如下

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:@" "];