我如何把一个Int在C＃中的字符串不使用的ToString（）？

问题描述

Since everything inherits from Object and Object has a ToString() method how would you convert an int to a string without using the native ToString() method?

The problem with string concatenation is that it will call ToString() up the chain until it hits one or hits the Object class.

How do you convert an integer to a string in C# without using ToString()?

解决方案

Something like this:

public string IntToString(int a)
{
    var chars = new[] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" };
    var str = string.Empty;
    if (a == 0)
    {
        str = chars[0];
    }
    else if (a == int.MinValue)
    {
        str = "-2147483648";
    }
    else
    {
        bool isNegative = (a < 0);
        if (isNegative)
        {
            a = -a;
        }

        while (a > 0)
        {
            str = chars[a % 10] + str;
            a /= 10;
        }

        if (isNegative)
        {
            str = "-" + str;
        }
    }

    return str;
}

---

Update: Here's another version which is shorter and should perform much better, since it eliminates all string concatenation in favor of manipulating a fixed-length array. It supports bases up to 16, but it would be easy to extend it to higher bases. It could probably be improved further:

public string IntToString(int a, int radix)
{
    var chars = "0123456789ABCDEF".ToCharArray();
    var str = new char[32]; // maximum number of chars in any base
    var i = str.Length;
    bool isNegative = (a < 0);
    if (a <= 0) // handles 0 and int.MinValue special cases
    {
        str[--i] = chars[-(a % radix)];
        a = -(a / radix);
    }

    while (a != 0)
    {
        str[--i] = chars[a % radix];
        a /= radix;
    }

    if (isNegative)
    {
        str[--i] = '-';
    }

    return new string(str, i, str.Length - i);
}

这篇关于我如何把一个Int在C＃中的字符串不使用的ToString（）？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！