java.util.concurrent.ConcurrentLinkedDeque.getFirst()方法是Java中的內置方法,它返回雙端隊列容器的第一個元素。
用法:
Conn_Linked_Deque.getFirst()
參數:該方法不接受任何參數。
返回值:該方法返回雙端隊列中存在的第一個元素。
異常:當雙端隊列為空時,該函數將引發NoSuchElementException。
以下示例程序旨在說明ConcurrentLinkedDeque.getFirst()方法:
程序1:
/* Java Program to Demonstrate getFirst()
method of ConcurrentLinkedDeque */
import java.util.concurrent.*;
class GFG {
public static void main(String[] args)
{
// Creating an empty Deque
ConcurrentLinkedDeque<String> cld =
new ConcurrentLinkedDeque<String>();
// Add elements into the Deque
cld.add("Welcome");
cld.add("To");
cld.add("Geeks");
cld.add("4");
cld.add("Geeks");
// Displaying the Deque
System.out.println("Elements in the Deque: " + cld);
// Displaying the first element
System.out.println("The first element is: " +
cld.getFirst());
}
}
輸出:
Elements in the Deque: [Welcome, To, Geeks, 4, Geeks] The first element is: Welcome
示例2:
/* Java Program to Demonstrate getFirst()
method of ConcurrentLinkedDeque */
import java.util.concurrent.*;
class GFG {
public static void main(String[] args)
{
// Creating an empty Deque
ConcurrentLinkedDeque<Integer> cld =
new ConcurrentLinkedDeque<Integer>();
try {
// Displaying the first element
System.out.println("The first element "
+ "is: " + cld.getFirst());
}
catch (Exception e) {
System.out.println(e);
}
// Add elements into the Deque
cld.add(12);
cld.add(43);
cld.add(29);
cld.add(16);
cld.add(70);
// Displaying the Deque
System.out.println("Elements in the Deque: " + cld);
// Displaying the first element
System.out.println("The first element is: " +
cld.getFirst());
}
}
輸出:
java.util.NoSuchElementException Elements in the Deque: [12, 43, 29, 16, 70] The first element is: 12
參考: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentLinkedDeque.html#getFirst()
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注:本文由純淨天空篩選整理自RICHIK BHATTACHARJEE大神的英文原創作品 ConcurrentLinkedDeque getFirst() method in Java。非經特殊聲明,原始代碼版權歸原作者所有,本譯文未經允許或授權,請勿轉載或複製。