C#中用foreach语句遍历数组及将数组作为参数的用法
对数组使用 foreach int[] numbers = { 4,5,6,1,2,3,-2,-1,0 }; foreach (int i in numbers) { System.Console.Write("{0} ",i); } // Output: 4 5 6 1 2 3 -2 -1 0
int[,] numbers2D = new int[3,2] { { 9,99 },{ 3,33 },{ 5,55 } }; // Or use the short form: // int[,] numbers2D = { { 9,55 } }; foreach (int i in numbers2D) { System.Console.Write("{0} ",i); } 输出: 9 99 3 33 5 55 但对于多维数组,使用嵌套的 for 循环可以更好地控制数组元素。 将数组作为参数传递 int[] theArray = { 1,7,9 }; PrintArray(theArray); 下面的代码显示 print 方法的部分实现。 void PrintArray(int[] arr) { // Method code. } 您可以在一个步骤中初始化和传递新数组,如下面的示例所示。 PrintArray(new int[] { 1,9 }); 示例 class ArrayClass { static void PrintArray(string[] arr) { for (int i = 0; i < arr.Length; i++) { System.Console.Write(arr[i] + "{0}",i < arr.Length - 1 ? " " : ""); } System.Console.WriteLine(); } static void ChangeArray(string[] arr) { // The following attempt to reverse the array does not persist when // the method returns,because arr is a value parameter. arr = (arr.Reverse()).ToArray(); // The following statement displays Sat as the first element in the array. System.Console.WriteLine("arr[0] is {0} in ChangeArray.",arr[0]); } static void ChangeArrayElements(string[] arr) { // The following assignments change the value of individual array // elements. arr[0] = "Sat"; arr[1] = "Fri"; arr[2] = "Thu"; // The following statement again displays Sat as the first element // in the array arr,inside the called method. System.Console.WriteLine("arr[0] is {0} in ChangeArrayElements.",arr[0]); } static void Main() { // Declare and initialize an array. string[] weekDays = { "Sun","Mon","Tue","Wed","Thu","Fri","Sat" }; // Pass the array as an argument to PrintArray. PrintArray(weekDays); // ChangeArray tries to change the array by assigning something new // to the array in the method. ChangeArray(weekDays); // Print the array again,to verify that it has not been changed. System.Console.WriteLine("Array weekDays after the call to ChangeArray:"); PrintArray(weekDays); System.Console.WriteLine(); // ChangeArrayElements assigns new values to individual array // elements. ChangeArrayElements(weekDays); // The changes to individual elements persist after the method returns. // Print the array,to verify that it has been changed. System.Console.WriteLine("Array weekDays after the call to ChangeArrayElements:"); PrintArray(weekDays); } } 输出: Sun Mon Tue Wed Thu Fri Sat arr[0] is Sat in ChangeArray. Array weekDays after the call to ChangeArray: Sun Mon Tue Wed Thu Fri Sat arr[0] is Sat in ChangeArrayElements. Array weekDays after the call to ChangeArrayElements: Sat Fri Thu Wed Thu Fri Sat 将多维数组作为参数传递 int[,] theArray = { { 1,2 },{ 2,3 },4 } }; Print2DArray(theArray); 下面的代码显示 print 方法的部分声明,该方法接受一个二维数组作为其参数。 void Print2DArray(int[,] arr) { // Method code. } 您可以在一个步骤中初始化和传递新数组,如下面的示例所示。 Print2DArray(new int[,] { { 1,4 },6 },{ 7,8 } }); 示例 class ArrayClass2D { static void Print2DArray(int[,] arr) { // Display the array elements. for (int i = 0; i < arr.GetLength(0); i++) { for (int j = 0; j < arr.GetLength(1); j++) { System.Console.WriteLine("Element({0},{1})={2}",i,j,arr[i,j]); } } } static void Main() { // Pass the array as an argument. Print2DArray(new int[,8 } }); // Keep the console window open in debug mode. System.Console.WriteLine("Press any key to exit."); System.Console.ReadKey(); } } 输出: Element(0,0)=1 Element(0,1)=2 Element(1,0)=3 Element(1,1)=4 Element(2,0)=5 Element(2,1)=6 Element(3,0)=7 Element(3,1)=8 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |