c#从字符串中删除目标字符串

[dapeng925]

有人名字符串：张一,王二,李三,王小汪,莉莉 ，这个字符串格式是这样用,分割，长短不定，人名位置不定。
我要删除某个名字，这个要删除的名字是个变量，位置也不确定（开头，中间，结尾）
最好用正则实现（我不会。。。）

[threenewbee]

用replace string s = "张一,王二,李三,王小汪,莉莉"; string del = ",李三"; s = s.Replace(del, "");'

[tcmakebest]

这个代码没用正则

        static void Main()
        {
            string s = RemoveNameA("a,b,c,d,e", "c");
            Debug.WriteLine(s);
            string t = RemoveNameB("a,b,c,d,e", "c,e");
            Debug.WriteLine(t);
        }
        // 删除一组名字
        private static string RemoveNameB(string source, string names)
        {
            List<string> list = new List<string>(source.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries));
            List<string> del = new List<string>(names.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries));
            list.RemoveAll(x => del.Contains(x));
            return string.Join(",", list.ToArray());
        }
        // 只能删除一个名称
        private static string RemoveNameA(string source, string name)
        {
            return AddDuoHao(source).Replace(AddDuoHao(name), ",").Trim(',');
        }

        private static string AddDuoHao(string s)
        {
            return "," + s + ",";
        }

[xuzuning]

            var s = "张一,王二,李三,王小汪,莉莉";
            //正则
            Console.WriteLine(Regex.Replace(s, string.Format("(?<=^|,){0}(,|$)", "张一"), ""));
            Console.WriteLine(Regex.Replace(s, string.Format("(?<=^|,){0}(,|$)", "莉莉"), ""));
            Console.WriteLine(Regex.Replace(s, string.Format("(?<=^|,){0}(,|$)", "李三"), ""));

            //字符串+集合
            var r = s.Split(',').Except(new string[] { "王二" });
            Console.WriteLine(string.Join(",", r));

[dapeng925]

引用 3 楼 xuzuning 的回复:

            var s = "张一,王二,李三,王小汪,莉莉";
            //正则
            Console.WriteLine(Regex.Replace(s, string.Format("(?<=^|,){0}(,|$)", "张一"), ""));
            Console.WriteLine(Regex.Replace(s, string.Format("(?<=^|,){0}(,|$)", "莉莉"), ""));
            Console.WriteLine(Regex.Replace(s, string.Format("(?<=^|,){0}(,|$)", "李三"), ""));

            //字符串+集合
            var r = s.Split(',').Except(new string[] { "王二" });
            Console.WriteLine(string.Join(",", r));

可行，就是如果删除的是最后一个，逗号去不掉。比如第二行，去掉 莉莉 那个，最后还会有个逗号，这个怎么办？

[娃都会打酱油了]

@"(,)?\b张三\b(,)?"

要在替换方法里面判断m.Groups[1].Success和m.Groups[2].Success，只有当两者都匹配时，替换为逗号，否则替换为空 算了，直接上代码吧

string[] arr = { "大一,张三,李四,王五", "大一,张三", "张三,李四" };
foreach (var str in arr)
{
    Console.WriteLine(Regex.Replace(str, @"(,)?\b张三\b(,)?", m =>
    {
        if (m.Groups[1].Success && m.Groups[2].Success)
        {
            return ",";
        }
        return string.Empty;
    }));
}

[xuzuning]

我也知道的，截图中就是这样 可以考虑在替换后 Trim(",")

[Poopaye]

string names = "张一,王二,李三,王小汪,莉莉"; string filter = "李三"; var result =string.Join(",", names.Split(',').Where(x => x != filter));

[千杯不醉-sen]

            string names = "张一,王二,李三,王小汪,莉莉";
            string filter = "李三";
            string res = names.Replace(filter + ",", "").Replace("," + filter, "");

[千杯不醉-sen]

            string names = "张一,王二,李三,王小汪,莉莉";
            string filter = "李三";
            string res = names.Replace(filter, "").Replace(",,", ",");