> **`ConcurrentLinkedDeque`** is thread-safe, unbounded deque. The `null` value is not permitted as an element. We can use `ConcurrentLinkedDeque` when multiple threads share a single deque.

The **`peek`** method can be used to get the first element of the `ConcurrentLinkedDeque` object.

#    
## Syntax 

---
```java
public E peek()
```
---


## Parameters

This method doesn’t take any parameters.


## Return value

The `peek` method retrieves the first element of the `deque` object. If the `deque` is empty, then `peek` returns `null`


## Code 

The code below demonstrates how to use the `peek` method.

import java.util.concurrent.ConcurrentLinkedDeque;
class Peek {
    public static void main( String args[] ) {
      ConcurrentLinkedDeque<String> deque = new ConcurrentLinkedDeque<>();
      deque.add("1");
      deque.add("2");
      deque.add("3");
      System.out.println("The deque is " + deque);

      System.out.println("deque.peek() returns : " + deque.peek());
    }
}

#    
## Explanation 

* Line 1: We import the `ConcurrentLinkedDeque` class.

* Line 4: We create a `ConcurrentLinkedDeque` object with the name `deque`. 

* Lines 5 to 7: We use the `add()` method of the `deque` object to add three elements (`"1"`,`"2"`,`"3"`) to the `deque`.

* Line 10: We use the `peek()` method of the `deque` object to get the first element of the `deque`. In our case, `peek()` returns `1`.

What is the ConcurrentLinkedDeque.peek() method in Java?

Syntax

Parameters

Return value

Code

Explanation