C# Array.TrueForAll()用法及代码示例

此方法用于确定数组中的每个元素是否与指定谓词定义的条件匹配。

用法:

public static bool TrueForAll (T[] array, Predicate<T> match);

在此，T是数组元素的类型。

参数：

array:它是一维，从零开始的数组，用于检查条件。
match:谓词定义了检查元素的条件。

返回值：如果数组中的每个元素都匹配指定谓词定义的条件，则此方法返回true，否则返回false。如果数组中没有元素，则返回值为true。

异常：如果数组为null或match为null，则此方法抛出ArgumentNullException。

以下示例程序旨在说明Array.TrueForAll(T []，Predicate)方法的用法：

示例1:

// C# program to demonstrate 
// TrueForAll() method 
using System; 
using System.Collections.Generic; 
  
public class GFG { 
  
// Main Method 
public static void Main() 
{ 
  
    try { 
  
        // Creating and intializing new the String 
        String[] myArr = {"Sun", "Son", "Sue", "Shu"}; 
  
        // Display the values of the myArr. 
        Console.WriteLine("Initial Array:"); 
  
        // calling the PrintIndexAndValues() 
        // method to print 
        PrintIndexAndValues(myArr); 
  
        // getting the bool value  
        // with required condition 
        // using method TrueForAll() 
        bool value = Array.TrueForAll(myArr, element => element.StartsWith("S", 
                                                    StringComparison.Ordinal)); 
  
        // Checking the condition 
        if (value) 
            Console.Write("Every Element is satisfying condition"); 
        else
            Console.Write("Every Element is not satisfying condition"); 
    } 
    catch (ArgumentException 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(); 
} 
}

输出：

Initial Array:
Sun
Son
Sue
Shu

Every Element is satisfying condition

示例2:对于ArgumentNullException

// C# program to demonstrate 
// TrueForAll() method 
// For ArgumentNullException 
using System; 
using System.Collections.Generic; 
  
public class GFG { 
  
// Main Method 
public static void Main() 
{ 
  
    try { 
  
        // Creating and initializing new  
        // the String with a null value 
        String[] myArr = null; 
  
        // getting the bool value  
        // with required condition 
        // using method TrueForAll() 
        Console.WriteLine("Trying to get the boolean "
                        +"value while myArr is null"); 
        Console.WriteLine(); 
        bool value = Array.TrueForAll(myArr, element => element.StartsWith("S", 
                                                    StringComparison.Ordinal)); 
  
        // Checking the condition 
        if (value) 
            Console.Write("Every Element is satisfying condition"); 
        else
            Console.Write("Every Element is not satisfying condition"); 
    } 
    catch (ArgumentException 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(); 
} 
}

输出：

Trying to get the boolean value while myArr is null

Exception Thrown: System.ArgumentNullException

参考：

https://docs.microsoft.com/en-us/dotnet/api/system.array.trueforall?view=netframework-4.7.2

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注：本文由纯净天空筛选整理自RohitPrasad3大神的英文原创作品 C# | Array.TrueForAll() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。