C# |数组。FindLast()方法
原文:https://www . geesforgeks . org/c-sharp-array-find last-method/
此方法用于搜索与指定谓词定义的条件相匹配的元素,返回整个数组中最后一次出现的。
语法:
public static T FindLast<T> (T[] array, Predicate<T> match);
参数:
数组:是一维的,从零开始搜索的数组。 匹配:是定义要搜索的元素的条件的谓词。
返回值:如果找到匹配指定谓词定义的条件的最后一个元素,则该方法返回该元素,否则返回类型 t 的默认值
异常:如果阵为空或匹配为空,则此方法抛出 ArgumentNullException 。
下面的程序说明了数组的使用。FindLast(T[],谓词)方法 :
例 1:
c sharp . c sharp . c sharp . c sharp
// C# program to demonstrate
// Array.FindLast(T[], Predicate<T>)
// Method
using System;
using System.Collections.Generic;
public class GFG {
// Main Method
public static void Main()
{
try {
// Creating and initializing
// new the String
String[] myArr = {"Sun", "Son", "Tue", "Thu"};
// Display the values of the myArr.
Console.WriteLine("Initial Array:");
// calling the PrintIndexAndValues()
// method to print
PrintIndexAndValues(myArr);
// getting a last element with required
// condition using method FindLast()
string value = Array.FindLast(myArr,
element => element.StartsWith("S",
StringComparison.Ordinal));
// Display the value of
// the found element.
Console.Write("Last occurrence: ");
// printing the string
// following the condition
Console.Write("{0}", value);
}
catch (ArgumentNullException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(String[] myArr)
{
for (int i = 0; i < myArr.Length; i++) {
Console.WriteLine("{0}", myArr[i]);
}
Console.WriteLine();
}
}
Output:
Initial Array:
Sun
Son
Tue
Thu
Last occurrence: Son
例 2:
c sharp . c sharp . c sharp . c sharp
// C# program to demonstrate
// Array.FindLast(T[], Predicate<T>)
// Method
using System;
using System.Collections.Generic;
public class GFG {
// Main Method
public static void Main()
{
try {
// Creating and initializing
// new Array String with null
String[] myArr = null;
// getting a last element with required
// condition using method FindLast()
string value = Array.FindLast(myArr,
element => element.StartsWith("S",
StringComparison.Ordinal));
// Display the value of
// the found element.
Console.Write("Last occurrence: ");
// printing the string
// following the condition
Console.Write("{0}", value);
}
catch (ArgumentNullException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(String[] myArr)
{
for (int i = 0; i < myArr.Length; i++) {
Console.WriteLine("{0}", myArr[i]);
}
Console.WriteLine();
}
}
Output:
Exception Thrown: System.ArgumentNullException
参考:
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