Java ArrayDeque 中的 pop() 和 remove() 有本质区别吗？

Question

Both remove and pop remove and return an element from the front of the Queue. They both throw an exception if there's an empty Queue.

Answer 1

There is no difference. In fact, pop() and remove() methods both call removeFirst. See https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/ArrayDeque.java

public E remove() {
    return removeFirst();
}

public E pop() {
    return removeFirst();
}

Answer 2

Both the methods internally calls removeFirst(), so there is not difference. ArrayDeque can be used as stack as well as LinkedList hence we have different interfaces, based on how we want to use it (as a stack, queue or linkedlist). It was introduced in version 1.6 of java API which is much later than Stack and LinkedList. As per oracle documentation

ArrayDeque class is likely to be faster than Stack when used as a stack, and faster than LinkedList when used as a queue.

public E remove() {
    return removeFirst();
}

public E pop() {
    return removeFirst();
}