The following is the specification of useful members of a Java (generic) stack handling class useful in developing translators. The closely equivalent C# (generic) version appears lower on this page.
The earlier versions of Java and C# did not have generic versions of these classes, but worked with elements of the Object class, which necessitated casting operations.
import java.util.*;
class Stack<E>
// Class for constructing a stack of elements of type E in Java
public Stack<E>()
// Empty stack constructor
public void push(E element)
// Appends element to top of stack
public E pop()
// Retrieves an element from top of stack
public E peek()
// Returns element on top of stack without removing it
public void clear()
// Clears all elements from stack
public int size()
// Returns number of elements in stack
public boolean empty()
// Returns true if stack is empty
public boolean contains(E element)
// Returns true if element is in the stack
} // Stack
Here is a sample program showing the use of this library
import library.*;
import java.util.*;
class ShowGenericStack {
// Demonstrate simple application of the generic Stack class in Java
static class Entry {
public String name;
public int age; // other fields could be added
public Entry(String name, int age) { // constructor
this.name = name;
this.age = age;
}
} // Entry
static Stack<Entry> stack = new Stack<Entry>(); // global for simplicity here!
public static void main (String[] args) {
// Build a stack of people's names and ages
IO.writeLine("Supply a list of people's names and ages. CTRL-Z to terminate");
do {
String name = IO.readWord();
int age = IO.readInt();
IO.readLn();
if (!IO.eof()) stack.push(new Entry(name, age)); // add to top of stack
} while (!IO.eof());
IO.writeLine(stack.size() + " items stored"); // report size of stack
Entry patEntry = new Entry("Pat", 63); // that fellow again!
stack.push(patEntry);
if (stack.contains(patEntry)) { // well, it must do!
IO.writeLine("Pat is on top of it, as always!");
IO.writeLine("Not bad for one who is only " + stack.peek().age);
}
while (!stack.empty()) // names in reverse order
IO.writeLine(stack.pop().name);
} // main
} // ShowGenericStack
The following is the specification of useful members of a C# 2.0 generic stack handling class useful in developing translators. A closely equivalent Java version appears earlier on this page.
The earlier versions of Java and C# did not have generic versions of these classes, but worked with elements of the Object class, which necessitated casting operations.
using System.Collections.Generic;
class Stack<E>
// Class for constructing a stack of elements of type E
public Stack<E>()
// Empty stack constructor
public void Push(E element)
// Appends element to top of stack
public E Pop()
// Retrieves an element from top of stack
public E Peek()
// Returns element on top of stack without removing it
public void Clear()
// Clears all elements from stack
public int Count { get; }
// Returns number of elements in stack
public boolean Contains(E element)
// Returns true if element is in the stack
} // Stack
Here is a sample program like the one given earlier showing the use of this library
using Library;
using System.Collections.Generic;
using System.Text;
class ShowGenericStack {
// Demonstrate simple application of the generic Stack class (C# version 2.0)
class Entry {
public string name;
public int age; // other fields could be added
public Entry(string name, int age) { // constructor
this.name = name;
this.age = age;
}
} // Entry
static Stack<Entry> stack = new Stack<Entry>(); // global for simplicity here!
public static void Main (string[] args) {
// Build a list of people's names and ages
IO.WriteLine("Supply a list of people's names and ages. CTRL-Z to terminate");
do {
string name = IO.ReadWord();
int age = IO.ReadInt();
IO.ReadLn();
if (!IO.EOF()) stack.Push(new Entry(name, age)); // add to top of stack
} while (!IO.EOF());
IO.WriteLine(stack.Count + " items stored"); // report size of stack
Entry patEntry = new Entry("Pat", 63); // that fellow again!
stack.Push(patEntry);
if (stack.Contains(patEntry)) { // well, it must do!
IO.WriteLine("Pat is on top of it, as always!");
IO.WriteLine("Not bad for one who is only " + stack.Peek().age);
}
while (stack.Count != 0) // names in reverse order
IO.WriteLine(stack.Pop().name);
} // Main
} // ShowGenericStack
Revised: 2014/03/13