字符串空格和回车处理

    //待处理的字符串

    NSString *string =
@" A B  CD   EFG\n MN\n";

    

    //字符串替换，处理后的string1
＝ @"ABCDEF\nMN\n";

    NSString *string1 =
[string
stringByReplacingOccurrencesOfString:@" "
withString:@""];

    

    //去除两端空格(注意是两端),处理后的string2
＝ @"A B  CD   EFG\n MN\n";

    NSString *string2 =
[string
stringByTrimmingCharactersInSet:[NSCharacterSet
whitespaceCharacterSet]];

    

    //去除两端回车(注意是两端),处理后的string3
＝ @" A B  CD   EFG\n MN";

    NSString *string3 =
[string
stringByTrimmingCharactersInSet:[NSCharacterSet
newlineCharacterSet]];

    

    //去除两端空格和回车(注意是两端),处理后的string4
＝ @"A B  CD   EFG\n MN";

    NSString *string4 =
[string
stringByTrimmingCharactersInSet:[NSCharacterSet
whitespaceAndNewlineCharacterSet]];