先决条件:C#中的索引器
多维索引器几乎类似于多维数组。为了有效地基于内容检索数据,使用了多维索引器。要创建多维索引器,您必须在索引器声明的参数列表中至少传递两个参数。要访问多维索引器的单个元素,请使用整数下标。每个下标都对一个维度进行索引,例如第一个对行维度进行索引,第二个对列维度进行索引,依此类推。
示例1:使用get和set访问器
// C# program to illustrate the
// Multidimensional Indexers
using System;
class GFG {
// reference to underlying 2D array
int[, ] data = new int[5, 5];
// declaring Multidimensional Indexer
public int this[int index1, int index2]
{
// get accessor
get
{
// it returns the values which
// read the indexes
return data[index1, index2];
}
// set accessor
set
{
// write the values in 'data'
// using value keyword
data[index1, index2] = value;
}
}
}
// Driver Class
class Geeks {
// Main Method
public static void Main(String []args)
{
// creating the instance of
// Class GFG as "index"
GFG index = new GFG();
// assign the values accordingly to
// the indexes of the array
// 1st row
index[0, 0] = 1;
index[0, 1] = 2;
index[0, 2] = 3;
// 2nd row
index[1, 0] = 4;
index[1, 1] = 5;
index[1, 2] = 6;
// 3rd row
index[2, 0] = 7;
index[2, 1] = 8;
index[2, 2] = 9;
// displaying the values
Console.WriteLine("{0}\t{1}\t{2}\n{3}\t{4}\t{5}\n{6}\t{7}\t{8}",
index[0, 0], index[0, 1], index[0, 2],
index[1, 0], index[1, 1], index[1, 2],
index[2, 0], index[2, 1], index[2, 2]);
}
}
输出:
1 2 3
4 5 6
7 8 9
示例2:不使用“ set”访问器,即仅使用只读属性
// C# program to illustrate the Multidimesional
// Indexer without using set accessor
using System;
class GFG {
// default constructor
public GFG() {}
// Multidimesional Indexer
public int this[int i1, int i2]
{
// get accessor
get
{
// read only properties
return (i1 + i2);
}
// No set accessor used
}
// Main Method
public static void Main(String []args)
{
// creating object of class
// "GFG" as "index"
GFG index = new GFG();
// displaying the values
for (int i = 0; i <= 2; i++) {
for (int j = 1; j <= 3; j++)
{
Console.Write(index[i, j] + "\t");
}
Console.WriteLine();
}
}
}
输出:
1 2 3
2 3 4
3 4 5