正则表达式

C#交互窗口内使用：

 1. 是否为double

> using System.Text.RegularExpressions;
> bool isMatch = Regex.IsMatch("652",@"^d{6}$");
> Console.Write(isMatch);
False
> bool isMatch = Regex.IsMatch("476800",@"^d{6}$");
> Console.Write(isMatch);
True



Regex RegNumber = new Regex("^[0-9]+(\.[0-9]+)?$");  //  判断是否为double

 2. 判断 0-100 正整数

[TestMethod]
        public void TestMethod1()
        {
            //   /^(0|[1-9]d|100)$/
            string regexString = "^(100|[1-9]\d|\d)$";
            for (int i = 0; i < 100; i++)
            {
                Assert.AreEqual(true,Regex.IsMatch(i.ToString(),regexString));
            }
            Assert.AreEqual(false, Regex.IsMatch("-1", regexString));
            Assert.AreEqual(false, Regex.IsMatch("-01", regexString));
            Assert.AreEqual(false, Regex.IsMatch("-10", regexString));
            Assert.AreEqual(false, Regex.IsMatch("-100", regexString));
            Assert.AreEqual(false, Regex.IsMatch("101", regexString));
            Assert.AreEqual(false, Regex.IsMatch("20.6", regexString));
            Assert.AreEqual(false, Regex.IsMatch("99.99", regexString));
            Assert.AreEqual(false, Regex.IsMatch("0.99", regexString));
            Assert.AreEqual(false, Regex.IsMatch("1001", regexString));
            Assert.AreEqual(false, Regex.IsMatch("10001", regexString));
        }