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Java Deque removeFirstOccurrence()用法及代碼示例


Deque 接口的 removeFirstOccurrence() 方法用於從雙端隊列中刪除給定元素的第一次出現。如果雙端隊列中沒有元素，則它保持不變。如果 deque 包含指定的元素，它可能返回 true。

用法:

boolean removeFirstOccurrence(Object o)

參數：

以上隻需要一個參數：

  1. 需要從給定雙端隊列中刪除 d 的元素 'o'。

返回：

如果從雙端隊列中刪除特定元素，則上述方法返回 true。

拋出：

  • ClassCastException- 如果給定元素的類與給定雙端隊列不兼容。
  • NullPointerException - 如果指定的元素已經為空並且給定的雙端隊列不允許空元素。

例子1

import java.util.ArrayDeque;
import java.util.Deque;

public class JavaDequeremoveFirstoccurrenceExample1 {
    public static void main(String[] args) {	
    	Deque<Character> deque = new ArrayDeque<>();
	    deque.push('d');
	    deque.push('c');
	    deque.push('b');
	    deque.push('a');
	    Boolean val = deque.removeFirstOccurrence('c');
	    System.out.println("The character is already present? "+val);
	  System.out.println("The final deque is given as:");   
	  for (Character character:deque) {
		System.out.println(character);
	}
   }
}

輸出：

The character is already present? true
The final deque is given as:
a
b
d

例子2

import java.util.ArrayDeque;
import java.util.Deque;
public class JavaDequeremoveFirstoccurrenceExample2 {
    public static void main(String[] args) {	
    	Deque<Integer> deque = new ArrayDeque<>();
	    deque.push(2);
	    deque.push(5);
	    deque.push(6);
	    deque.push(7);
	    Boolean val = deque.removeFirstOccurrence(5);
	    System.out.println("The intger value is already preesnt? "+val);
	  System.out.println("The final deque is given as:");   
	  for (Integer integer:deque) {
		System.out.println(integer);
	}
   }
}

輸出：

The integer value is already preesnt? true
The final deque is given as:
7
6
2

例子3

import java.util.ArrayDeque;
import java.util.Deque;
public class JavaDequeremoveFirstoccurrenceExample3 {
    public static void main(String[] args) {	
    	Deque<Float> deque = new ArrayDeque<>();
	    deque.push(66.8f);
	    deque.push(50.8f);
	    deque.push(63.4f);
	    deque.push(71.2f);
	    Boolean val = deque.removeFirstOccurrence(5);
	    System.out.println("The float value is already preesnt? "+val);
	  System.out.println("The final deque is given as:");   
	 for (Float float1:deque) {
		System.out.println(float1);
	}
   }
}

輸出：

The float value is already preesnt? false
The final deque is given as:
71.2
63.4
50.8
66.8




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注：本文由純淨天空篩選整理自 Java Deque removeFirstOccurrence() Method。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。