三种常用的字符串判空串方法： 1: bool isEmpty = (str.Length == 0); 2: bool isEmpty = (str == String.Empty); 3: bool isEmpty = (str == ""); 哪种方法最快？
以下是测试代码：
using System; public class strLengthTime { public static void Main() { string strTest = ""; string strSub; for (int i = 0; i < 1000; i++) { strSub = i.ToString(); strTest = strTest + strSub; } DateTime startTime; DateTime endTime; TimeSpan timeCost; startTime = DateTime.Now; for (int m = 0; m < 100000000; m++) { if (strTest.Length == 0) { } } endTime = DateTime.Now; timeCost = endTime - startTime; System.Console.WriteLine("strTest.Length Method Costs:" + timeCost.TotalMilliseconds.ToString()); startTime = DateTime.Now; for (int m = 0; m < 100000000; m++) { if (strTest == string.Empty) { } } endTime = DateTime.Now; timeCost = endTime - startTime; System.Console.WriteLine("String.Empty Method Costs:" + timeCost.TotalMilliseconds.ToString()); startTime = DateTime.Now; for (int m = 0; m < 100000000; m++) { if (strTest == "") { } } endTime = DateTime.Now; timeCost = endTime - startTime; System.Console.WriteLine("The Third Method Costs:" + timeCost.TotalMilliseconds.ToString()); Console.ReadLine(); } }
执行结果：
string.Length==0方法的速度最快。
于是在今后的比较空串的时候，请多用 string.Length==0。
转载于:https://www.cnblogs.com/nanshouyong326/archive/2009/02/23/1396307.html
