Question

如何在c＃中使用C语言的strchr函数。请给我一些指导......

Answer 1

string.IndexOf

Answer 2

string.IndexOf就是答案。

但是，如果您正在寻找

strchr功能 returns to the first occurrence of Character to be located in string, or NULL if c is not found

你可以做如下的事情：

创建一个函数

        /// <summary>
        /// Function: Strchr
        /// Returns the first occurrence of Character to be located 
        /// in string or null otherwise
        /// </summary>
        /// <param name="originalString"></param>
        /// <param name="charToSearch"></param>
        /// <returns></returns>
        private int? Strchr(string originalString,char charToSearch)
        {
            int? found = originalString.IndexOf(charToSearch);
            return found > -1 ? found : null;
        }

并将其称为：

string test = "hello";
int? res = Strchr(test, '3'); //Returns null
int? res = Strchr(test, 'h'); //Returns 0

希望这能回答你的问题。

Answer 3

上面的答案似乎并没有100％理解strchr（）的契约，也没有提供真正的直接替换......它通常会返回一个指向从该字符开始的字符串的指针（不是索引）。

A＆＃34;更纯粹＆＃34;实现：

警告：不确定这是否尽可能纯，因为它可能会提供一个 new 字符串而不是指向原始字符串，就像在C ++中一样。可能无法获得真正的substr指针。但我自己并不是C＃专家。

    /// <summary>
    /// C++ strchr Equivalent
    /// </summary>
    /// Let you fill out the stupid <param ...> tags.
    private string strchr(string originalString, char charToSearch)
    {
        int found = originalString.IndexOf(charToSearch);
        return found > -1 ? originalString.Substring(found) : null;
    }

但是我也发现这个实现更好b / c你可以简单地对字符串进行+ 1 +的C ++ ptr数学运算来获得终结符...

    /// <summary>
    /// C++ strchr Equivalent (with jump past character option)
    /// </summary>
    /// <param name="originalString"></param>
    /// <param name="charToSearch"></param>
    /// <param name="pastIt"></param>
    /// <returns>String starting at the search char</returns>
    private string strchr(string originalString, char charToSearch, bool pastIt)
    {
        int found = originalString.IndexOf(charToSearch);
        return found > -1 ? originalString.Substring(found + (pastIt ? 1 : 0)) : null;
    }

    /// <summary>
    /// C++ strchr Equivalent (Pure)
    /// </summary>
    private string strchr(string originalString, char charToSearch)
    {
        return strchr(originalString, charToSearch, false);
    }

如何在c＃中找到strchr函数

3 个答案: