Stack peek() in Java

peek(): This method is available in java.util.Stack class of Java.

Syntax:

K java.util.Stack.peek()

This method looks at the object at the top of this stack without removing it from the stack.

Parameters: NA

Returns: the object at the top of this stack.

Throws:

EmptyStackException - if this stack is empty.

Approach 1: When no exception

Java

import java.util.Stack;

public class Stackpeek {
    public static void main(String[] args) {

        Stack<Integer> st = new Stack<>();

        st.push(1);
        st.push(18);
        st.push(29);
        st.push(8);

        System.out.println(st.peek());

    }
}

Output:

8

Approach 2: EmptyStackException 

Java

import java.util.Stack;

public class Stackpeek {
    public static void main(String[] args) {

        Stack<Integer> st = new Stack<>();

        System.out.println(st.peek());

    }
}

Output:

Exception in thread "main" java.util.EmptyStackException
	at java.base/java.util.Stack.peek(Stack.java:101)