去空格 whitespaceAndNewlineCharacterSet

本文转载至 http://blog.csdn.net/samuelltk/article/details/8994313 

1.去掉两端的空格

[str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]

2.去掉多余的空格

NSString *str = @"    this     is a    test    .   ";

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

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

3.去掉所有空格

[str stringByReplacingOccurrencesOfString:@" " withString:@""]