Built-in Exception Classes

Exception

The superclass of all exceptions.

NoMemoryError

Thrown when attempting to reserve too much memory at once.

ScriptError

Indicates a script error.

NotImplementedError

Thrown when an unimplemented feature is invoked.

SyntaxError

Thrown by a syntax error.

StandardError

Without a class specified, the rescue class will catch the subclasses of this exception class.

ArgumentError

Thrown when argument numbers do not match or when the values are incorrect.

IndexError

Thrown when the index is out of range.

IOError

Thrown when an I/O error occurs.

EOFError

Thrown when EOF (End Of File) has been reached.

LocalJumpError

Thrown when no jump destination is found for a control structure.

NameError

Thrown when accessing an undefined local variable or constant.

NoMethodError

Thrown when calling an undefined method.

RangeError

A range exception. Thrown when an out-of-range integer conversion (from Bignum to Fixnum) , etc., occurs.

FloatDomainError

Thrown when trying to convert a positive or negative infinite number or NaN (Not a Number) into Bignum , or when comparing a number to a NaN.

RegexpError

Thrown when compiling a regular expression fails.

RuntimeError

A runtime exception. Thrown when calling raise without specifying an exception.

SystemCallError

Thrown when a system call fails.

Errno::EXXX

Exception class for each errno. See the Errno module for more on each class name.

SystemStackError

Thrown when a stack level becomes too deep.

TypeError

Thrown when an illegal type is invoked.

ZeroDivisionError

Thrown when dividing by zero.

SystemExit

Terminates the program. See exit for more information.

fatal

A fatal (internal) error. This object is not visible with normal methods.