Question

我需要检查字符串的开头和结尾是否包含任何逗号（，）并删除逗号（或）用空字符串替换这些逗号。

例如，

NSString *str1 = @",a,b,c,d,"; or

NSString *str1 = @",a,b,c,d"; or

NSString *str1 = @"a,b,c,d,";

输出：

NSString *str1 = @"a,b,c,d";

我试过这个

NSRange lastComma = [str1 rangeOfString:@"," options:NSBackwardsSearch];

        if(lastComma.location != NSNotFound) {
            str1 = [str1 stringByReplacingCharactersInRange:lastComma
                                                     withString: @""];
        }

并删除最后一个逗号，但如何删除第一个逗号？。

有没有办法做到这一点，欢迎帮助。

Answer 1

您可以使用[NSString componentsSeparatedByString:]然后拒绝所有空字符串。这样就可以删除列表中的空元素：

NSArray *elements = [inputString componentsSeparatedByString:@","]; NSMutableArray *outputElements = [[NSMutableArray alloc] init]; for (NSString *element in elements) if ([element length] > 0) [outputElements addObject:element];

然后重新格式化字符串：

NSString *outputString = [outputElements componentsJoinedByString:@","]

Answer 2

您可以使用stringByTrimmingCharactersInSet:的{{1}}方法。

NSSTring

Answer 3

从字符串的第一个和最后一个中删除逗号（如果有）。

  NSString *str1 = @",a,b,c,d,";

    NSLog(@"%@",[str1 substringFromIndex:str1.length - 1]);

    if ([[str1 substringToIndex:1] isEqualToString:@","])
    {

        str1 = [str1 substringFromIndex:1];

        NSLog(@" == %@",str1);

    }
    if([[str1 substringFromIndex:str1.length - 1] isEqualToString:@","])
    {
        str1 = [str1 substringToIndex:str1.length - 1];

        NSLog(@"%@",[str1 substringToIndex:str1.length - 1]);
    }

Answer 4

您可以使用字符串操纵器功能。 1.find_last_of 2.find_first_of（）

Answer 5

您可以使用stringByReplacingOccurrencesOfString:withString:options:range:方法替换＆＃39;，＆＃39;用＆＃39;＆＃39;。

参考下面的代码，

    int strLength = [str1 length];
    str1 = [str1 stringByReplacingOccurrencesOfString:@"," withString:@"" options:NSCaseInsensitiveSearch range:NSRangeFromString(@"0,1")];
    str1 = [str1 stringByReplacingOccurrencesOfString:@"," withString:@"" options:NSCaseInsensitiveSearch range:NSRangeFromString([NSString stringWithFormat:@"%d,%d",strLength - 1,1])];

Answer 6

NSString*delete=@"a,b,c,d,";
    if ([delete hasPrefix:@","] && [delete hasSuffix:@","]) 
         delete=[ [delete substringFromIndex:1] substringToIndex:delete.length-2];
    else if ([delete hasPrefix:@","])
        delete= [delete substringFromIndex:1];
    else
        delete=[delete substringToIndex:delete.length-1];
    NSLog(@"delete---%@",delete);

在ios中使用逗号开始和结束字符串

6 个答案: