Exceptions
PHP Manual

The UnexpectedValueException class

Introduction

Exception thrown if a value does not match with a set of values. Typically this happens when a function calls another function and espects the return value to be of a certain type or value not including arithmetic or buffer related errors.

Class synopsis

UnexpectedValueException extends RuntimeException {
/* Inherited methods */
final public string Exception::getMessage ( void )
final public Exception Exception::getPrevious ( void )
final public mixed Exception::getCode ( void )
final public string Exception::getFile ( void )
final public int Exception::getLine ( void )
final public array Exception::getTrace ( void )
final public string Exception::getTraceAsString ( void )
public string Exception::__toString ( void )
final private void Exception::__clone ( void )
}

Exceptions
PHP Manual