BestPractice-将字符串的第一个字符转换为小写 [英] BestPractice - Transform first character of a string into lower case

问题描述

我想拥有一种将字符串的第一个字符转换为小写字母的方法。

I'd like to have a method that transforms the first character of a string into lower case.

我的方法：

1。

public static string ReplaceFirstCharacterToLowerVariant(string name)
{
    return String.Format("{0}{1}", name.First().ToString().ToLowerInvariant(), name.Substring(1));
}

2。

public static IEnumerable<char> FirstLetterToLowerCase(string value)
{
    var firstChar = (byte)value.First();
    return string.Format("{0}{1}", (char)(firstChar + 32), value.Substring(1));
}

您的处理方式是什么？

推荐答案

我将使用简单的串联：

Char.ToLowerInvariant(name[0]) + name.Substring(1)

第一个解决方案未优化，因为 string.Format 速度很慢，如果格式永远不变，则不需要它。

The first solution is not optimized because string.Format is slow and you don't need it if you have a format that will never change. It also generates an extra string to covert the letter to lowercase, which is not needed.

使用 + 32的方法很丑陋/难以维护，因为它需要了解以下内容： ASCII字符值偏移量。还会生成带有Unicode数据和ASCII符号字符的错误输出。

The approach with "+ 32" is ugly / not maintainable as it requires knowledge of ASCII character value offsets. It will also generate incorrect output with Unicode data and ASCII symbol characters.

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