basics of stack (push, peek, size, pop)

stack_basic.java

@@ -0,0 +1,34 @@
+import java.util.*;
+public class Program
+{
+    public static void main(String[] args) 
+    {
+		Stack<Integer> st=new Stack<>();
+        st.push(10);
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.push(20);
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.push(30);
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.push(40);
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.push(50);
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.pop();
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.pop();
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.pop();
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.pop();
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.pop();
+        System.out.println(st+" "+st.peek()+" "+st.size());
+        st.pop();
+        //till here all elements are gone 
+        //so when we again print st.peek it will not print it will give run time error
+        //so we do not write st.peek function
+        System.out.println(st+" "+st.size());
+        //size comes as zero
+	}
+}