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Exception: KeyError

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::IndexError, ::StandardError, ::Exception
Instance Chain:
self, ::IndexError, ::StandardError, ::Exception
Inherits: IndexError
Defined in: error.c,
error.c

Overview

Raised when the specified key is not found. It is a subclass of ::IndexError.

h = {"foo" => :bar}
h.fetch("foo") #=> :bar
h.fetch("baz") #=> KeyError: key not found: "baz"

Class Attribute Summary

::Exception - Inherited

.to_tty?

Returns true if exception messages will be sent to a terminal device.

Class Method Summary

::Exception - Inherited

.exception

Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
.new

Returns a new exception object.

Instance Method Summary

::Exception - Inherited

#==

Returns whether object is the same class as self and its #message and #backtrace are equal to those of self.
#backtrace

Returns a backtrace value for self; the returned value depends on the form of the stored backtrace value:
#backtrace_locations

Returns a backtrace value for self; the returned value depends on the form of the stored backtrace value:
#cause

Returns the previous value of global variable $!, which may be nil (see Global Variables):
#detailed_message

Returns the message string with enhancements:
#exception

Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
#full_message

Returns an enhanced message string:
#inspect

Returns a string representation of self:
#message

Returns #to_s.
#set_backtrace

Sets the backtrace value for self; returns the given +value:
#to_s

Returns a string representation of self:

Constructor Details

.new(message = nil, receiver: nil, key: nil) ⇒ key_error

Construct a new KeyError exception with the given message, receiver and key.

[ GitHub ] 

  


# File 'error.c', line 2709



static VALUE
key_err_initialize(int argc, VALUE *argv, VALUE self)
{
    VALUE options;

    rb_call_super(rb_scan_args(argc, argv, "01:", NULL, &options), argv);

    if (!NIL_P(options)) {
        ID keywords[2];
        VALUE values[numberof(keywords)];
        int i;
        keywords[0] = id_receiver;
        keywords[1] = id_key;
        rb_get_kwargs(options, keywords, 0, numberof(values), values);
        for (i = 0; i < numberof(values); ++i) {
            if (!UNDEF_P(values[i])) {
                rb_ivar_set(self, keywords[i], values[i]);
            }
        }
    }

    return self;
}


  







Instance Method Details



  

    #key  ⇒ Object   



  

    

Return the key caused this KeyError exception.


  



  [ GitHub ]


  

  


# File 'error.c', line 2680



static VALUE
key_err_key(VALUE self)
{
    VALUE key;

    key = rb_ivar_lookup(self, id_key, Qundef);
    if (!UNDEF_P(key)) return key;
    rb_raise(rb_eArgError, "no key is available");
}


  








  

    #receiver  ⇒ Object   



  

    

Return the receiver associated with this KeyError exception.


  



  [ GitHub ]


  

  


# File 'error.c', line 2663



static VALUE
key_err_receiver(VALUE self)
{
    VALUE recv;

    recv = rb_ivar_lookup(self, id_receiver, Qundef);
    if (!UNDEF_P(recv)) return recv;
    rb_raise(rb_eArgError, "no receiver is available");
}