SymbolTable

java.lang.Object
- SymbolTable

```
public class SymbolTable
extends java.lang.Object
```
A table of symbols for a postscript interpreter. Uses java.util.HashMap for a simple, efficient implementation. We'll learn about the Map ADT and hashing soon.

Constructor Summary

Constructors
Constructor Description

SymbolTable()
Constructs empty symbol table

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`add(java.lang.String symbol, Token value)`	Add a string and associated token to the table
`boolean`	`contains(java.lang.String symbol)`	Check if a string is present in the table
`Token`	`get(java.lang.String symbol)`	Retrieve the token associated with a string from the table
`Token`	`remove(java.lang.String symbol)`	Remove a string and the associated token from the table
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - SymbolTable
```
public SymbolTable()
```
    Constructs empty symbol table
- Method Detail
  - contains
```
public boolean contains(java.lang.String symbol)
```
    Check if a string is present in the table
    
    Parameters:
    
    symbol - String to check for in the table
    
    Returns:
    
    true if symbol is in the table
  - add
```
public void add(java.lang.String symbol,
                Token value)
```
    Add a string and associated token to the table
    
    Parameters:
    
    symbol - String to add to the table
    
    value - Token to associate with symbol Note: if symbol is already in the table, its associated Token will be replaced with value
  - get
```
public Token get(java.lang.String symbol)
```
    Retrieve the token associated with a string from the table
    
    Parameters:
    
    symbol - String to retrieve from the table
    
    Returns:
    
    returns Token associated with symbol
  - remove
```
public Token remove(java.lang.String symbol)
```
    Remove a string and the associated token from the table
    
    Parameters:
    
    symbol - String to remove from the table
    
    Returns:
    
    Token associated with symbol (or null if symbol is not present in the table)
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    returns printable version of symbol table. Use with ptable.