Maintenance of Ruby 2.0.0 ended on February 24, 2016. Read more

In Files

  • complex.c
  • object.c
  • rational.c

NilClass

The class of the singleton object nil.

Public Instance Methods

false & obj → false click to toggle source
nil & 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.

 
               static VALUE
false_and(VALUE obj, VALUE obj2)
{
    return Qfalse;
}
false ^ obj → true or false click to toggle source
nil ^ obj → true or false

Exclusive Or—If obj is nil or false, returns false; otherwise, returns true.

 
               static VALUE
false_xor(VALUE obj, VALUE obj2)
{
    return RTEST(obj2)?Qtrue:Qfalse;
}
inspect → "nil" click to toggle source

Always returns the string “nil”.

 
               static VALUE
nil_inspect(VALUE obj)
{
    return rb_usascii_str_new2("nil");
}
nil?() click to toggle source

call_seq:

nil.nil?               -> true

Only the object nil responds true to nil?.

 
               static VALUE
rb_true(VALUE obj)
{
    return Qtrue;
}
rationalize([eps]) → (0/1) click to toggle source

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

 
               static VALUE
nilclass_rationalize(int argc, VALUE *argv, VALUE self)
{
    rb_scan_args(argc, argv, "01", NULL);
    return nilclass_to_r(self);
}
to_a → [] click to toggle source

Always returns an empty array.

nil.to_a   #=> []

 
               static VALUE
nil_to_a(VALUE obj)
{
    return rb_ary_new2(0);
}
to_c → (0+0i) click to toggle source

Returns zero as a complex.

 
               static VALUE
nilclass_to_c(VALUE self)
{
    return rb_complex_new1(INT2FIX(0));
}
to_f → 0.0 click to toggle source

Always returns zero.

nil.to_f   #=> 0.0

 
               static VALUE
nil_to_f(VALUE obj)
{
    return DBL2NUM(0.0);
}
to_h → {} click to toggle source

Always returns an empty hash.

nil.to_h   #=> {}

 
               static VALUE
nil_to_h(VALUE obj)
{
    return rb_hash_new();
}
to_i → 0 click to toggle source

Always returns zero.

nil.to_i   #=> 0

 
               static VALUE
nil_to_i(VALUE obj)
{
    return INT2FIX(0);
}
to_r → (0/1) click to toggle source

Returns zero as a rational.

 
               static VALUE
nilclass_to_r(VALUE self)
{
    return rb_rational_new1(INT2FIX(0));
}
to_s → "" click to toggle source

Always returns the empty string.

 
               static VALUE
nil_to_s(VALUE obj)
{
    return rb_usascii_str_new(0, 0);
}
false | obj → true or false click to toggle source
nil | obj → true or false

Or—Returns false if obj is nil or false; true otherwise.

 
               static VALUE
false_or(VALUE obj, VALUE obj2)
{
    return RTEST(obj2)?Qtrue:Qfalse;
}