UnknownVariableException

java.lang.Object
- java.lang.Throwable
- - java.lang.Exception
  - - java.lang.RuntimeException
    - - org.prolog4j.UnknownVariableException

All Implemented Interfaces:

Serializable
```
public class UnknownVariableException
extends RuntimeException
```
This exception is thrown when a syntactically incorrect Prolog query is processed.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor	Description
`UnknownVariableException(String variable)`	Constructs an UnknownVariableException.
`UnknownVariableException(String variable, Throwable cause)`	Constructs an UnknownVariableException.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

String getVariable()
Returns the name of the variable that caused the exception.
- Methods inherited from class java.lang.Throwable
  addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - UnknownVariableException
```
public UnknownVariableException(String variable)
```
    Constructs an UnknownVariableException. It takes the name of the absent variable as its argument. The exception is thrown when you want to get the value of a variable that does not occur in the query being processed.
    
    Parameters:
    
    variable - the name of the variable whose value was required but does not exist in the query
  - UnknownVariableException
```
public UnknownVariableException(String variable,
                                Throwable cause)
```
    Constructs an UnknownVariableException. It takes the name of the absent variable as its first argument. The exception is thrown when you want to get the value of a variable that does not occur in the query being processed. It takes the original exception (that has been thrown by the inherent Prolog implementation) as another argument.
    
    Parameters:
    
    variable - the name of the variable whose value was required but does not exist in the query
    
    cause - the original exception thrown by the implementation
- Method Detail
  - getVariable
```
public String getVariable()
```
    Returns the name of the variable that caused the exception.
    
    Returns:
    
    the name of the variable that is absent in the query being processed