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Class: NilClass

Relationships & Source Files
Inherits: Object
Defined in: object.c,
complex.c,
nilclass.rb,
object.c,
rational.c

Overview

The class of the singleton object nil.

Instance Attribute Summary

Instance Method Summary

Instance Attribute Details

#nil? ⇒ Boolean (readonly)

Only the object nil responds true to nil?.

[ GitHub ] 

  


# File 'object.c', line 1489



static VALUE
rb_true(VALUE obj)
{
    return Qtrue;
}


  







Instance Method Details



  

    

      #&(obj)  ⇒ false 
      #&(obj)  ⇒ false 
    

  



  

    

And—Returns false. obj is always evaluated as it is the argument to a method call—there is no short-circuit evaluation in this case.


  





  


  [ GitHub ]


  

  


# File 'object.c', line 1451



static VALUE
false_and(VALUE obj, VALUE obj2)
{
    return Qfalse;
}


  








  

    #===  
  

  [ GitHub ]






  

    #=~(other)  ⇒ nil   



  

    

Dummy pattern matching – always returns nil.



This method makes it possible to while gets =~ /re/ do.


  



  [ GitHub ]


  

  


# File 'object.c', line 1335



static VALUE
nil_match(VALUE obj1, VALUE obj2)
{
    return Qnil;
}


  








  

    #^  
  

  [ GitHub ]






  

    #inspect  ⇒ "nil"   



  

    

Always returns the string “nil”.


  



  [ GitHub ]


  

  


# File 'object.c', line 1320



static VALUE
nil_inspect(VALUE obj)
{
    return rb_usascii_str_new2("nil");
}


  








  

    #rationalize([eps])  ⇒ 1   



  

    

Returns zero as a rational.  The optional argument eps is always ignored.


  



  [ GitHub ]


  

  


# File 'rational.c', line 2124



static VALUE
nilclass_rationalize(int argc, VALUE *argv, VALUE self)
{
    rb_check_arity(argc, 0, 1);
    return nilclass_to_r(self);
}


  








  

    #to_a  ⇒ Array   



  

    

Always returns an empty array.



nil.to_a   #=> []


  



  [ GitHub ]


  

  


# File 'object.c', line 1290



static VALUE
nil_to_a(VALUE obj)
{
    return rb_ary_new2(0);
}


  








  

    #to_c  ⇒ (0+0i)   



  

    

Returns zero as a complex.


  



  [ GitHub ]


  

  


# File 'complex.c', line 1699



static VALUE
nilclass_to_c(VALUE self)
{
    return rb_complex_new1(INT2FIX(0));
}


  








  

    #to_f  ⇒ 0.0   



  

    

Always returns zero.



nil.to_f   #=> 0.0


  



  [ GitHub ]


  

  


# File 'nilclass.rb', line 22



def to_f
  return 0.0
end


  








  

    #to_h  ⇒ {}   



  

    

Always returns an empty hash.



nil.to_h   #=> {}


  



  [ GitHub ]


  

  


# File 'object.c', line 1307



static VALUE
nil_to_h(VALUE obj)
{
    return rb_hash_new();
}


  








  

    #to_i  ⇒ 0   



  

    

Always returns zero.



nil.to_i   #=> 0


  



  [ GitHub ]


  

  


# File 'nilclass.rb', line 10



def to_i
  return 0
end


  








  

    #to_r  ⇒ 1   



  

    

Returns zero as a rational.


  



  [ GitHub ]


  

  


# File 'rational.c', line 2111



static VALUE
nilclass_to_r(VALUE self)
{
    return rb_rational_new1(INT2FIX(0));
}


  








  

    #to_s  ⇒ ""   



  

    

Always returns the empty string.


  



  [ GitHub ]


  

  


# File 'object.c', line 1273



MJIT_FUNC_EXPORTED VALUE
rb_nil_to_s(VALUE obj)
{
    return rb_cNilClass_to_s;
}


  








  

    #|  
  

  [ GitHub ]