正在手搓 NumType 类型检查器, 它可以通过输入文本信息来判断这个文本它可以转换成什么类型, 挺复杂的, 在此过程了解了一些我没有见过的变量类型, 然后这两天又是为着边境检查, 选取范围感到苦恼, 不过现在已经把基础代码给写好了, 勉强能用, 暂时没有出现什么大Bug (但愿吧).
/// <summary>
/// 判断数字类型
/// </summary>
/// <param name="input">输入文本</param>
/// <returns>返回类型: null, string, int, long, float, double, decimal, biginteger</returns>
public static string NumType(string input)
{//忽略 Nullif (input == null){return "null";}else if(input.Length == 0){return "string";}string type = "string";char[] nums = {'1','2','3','4','5','6','7','8','9','0' };bool kexuejishufa = false; //是不是科学计数发for(int i = 0; i < input.Length; i++ ) //遍历文本{char t = input[i];if (i == 0 && (t == '-' || t == '+')) //是不是正负数{continue;}bool yes = false;foreach(char tt in nums) //诶个看看单个字是不是数字{if (tt == t){yes = true;break;}}if (t == 'e' || t == 'E') //科学计数发{if (kexuejishufa == true) //不可能有两个E{return "string";}else{yes = true;type = "float";kexuejishufa = true;}}else if(t == '-' || t == '+') //正负数的前面是不是 'E'{if (input[i - 1] == 'E' || input[i - 1] == 'e'){yes = true;}}else if (t == '.' && type != "float") //小数点{yes = true;type = "float";}if (yes == false) //都不是那只能是文本{return "string";}}//都跑到这里来的,说明是数字if (type != "float"){type = "int";}//然后判断大小if(type == "int") //这是整数{int int1 = 0;long long1 = 0;decimal decimal1 = 0;if (int.TryParse(input,out int1) == true) //32位整數{return "int";}else if (long.TryParse(input,out long1) == true) //64位整數{return "long";}else if (decimal.TryParse(input,out decimal1) == true) //128位數字{return "decimal";}else //超級無敵大{return "biginteger";}}else //这是浮点数{double double1 = 0;//去除符号if (input[0] == '-'){input = input.Substring(1);}//科学计数法展开if (kexuejishufa == true){int E = input.IndexOf("E", StringComparison.InvariantCultureIgnoreCase);//检查 E 旁边有没有数字if (E == 0 || E == input.Length - 1) // 1e{return "string";}else if(E == input.Length - 2 && (input[input.Length - 1] == '-' || input[input.Length - 1] == '+')) //1e+{return "string";}//获取 E 后边的数E = int.Parse(input.Substring(E + 1, input.Length - 1 - E));input = input.Substring(0, input.IndexOf("E", StringComparison.InvariantCultureIgnoreCase));int potindex = input.IndexOf(".");input = input.Replace(".", "");if (E < 0) //加小数点{int newpot = E + potindex;int length = input.Length;if (length > newpot) {for (int t = 0; t < newpot * -1 + 1; t++){input = "0" + input;}}}else //减小数点{int newpot = E + potindex;int length = input.Length;if (newpot > length) {for (int t = 0; t < newpot - length; t++){input = input + "0";}}//好像没必要再把小数点填回去, 后面只比对有多少位有效数字}//ConsoleLog(input);}//if (input.Substring(input.IndexOf("."), endindex).Length > 16 ||// input.Substring(0, input.IndexOf(".")).Length > 16) //高精度浮点input = input.Replace(".","");//继续比对if (input.Length > 17) //高精度浮点{return "decimal";}else{if (double1 > float.MaxValue) //双精度浮点{return "double";}//else if (input.Substring(input.IndexOf("."), endindex).Length > 7 ||// input.Substring(0, input.IndexOf(".")).Length > 7) //超过单精度范围还是双精度浮点else if (input.Length > 8){return "double";}else //单精度浮点{return "float";}}}
}