Class: NilClass

Inherits:

Object

• Object
• NilClass

Defined in:

object.c,
object.c more...

Overview

The class of the singleton object nil.

Instance Method Summary

• #&(obj2) ⇒ Object

  And—Returns false.

• #=== ⇒ Object
• #=~(other) ⇒ nil

  Dummy pattern matching – always returns nil.

• #^ ⇒ Object
• #inspect ⇒ Object

  Always returns the string “nil”.

• #nil? ⇒ true

  Only the object nil responds true to nil?.

• #rationalize([eps]) ⇒ Object

  Returns zero as a rational.

• #to_a ⇒ Object

  call-seq: nil.to_a -> [].

• #to_c ⇒ Object

  Returns zero as a complex.

• #to_f ⇒ 0.0

  Always returns zero.

• #to_h ⇒ Object

  call-seq: nil.to_h -> {}.

• #to_i ⇒ 0

  Always returns zero.

• #to_r ⇒ Object

  Returns zero as a rational.

• #to_s ⇒ Object

  Always returns the empty string.

• #| ⇒ Object

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.

Overloads:

• #&(obj) ⇒ false

  Returns:

  • (false)
• #&(obj) ⇒ false

  Returns:

  • (false)

# File 'object.c', line 1516

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

#=== ⇒ Object

#=~(other) ⇒ nil

Dummy pattern matching – always returns nil.

Returns:

• (nil)

# File 'object.c', line 1400

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

#^ ⇒ Object

#inspect ⇒ Object

Always returns the string “nil”.

# File 'object.c', line 1387

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

#nil? ⇒ true

Only the object nil responds true to nil?.

Returns:

• (true)

# File 'object.c', line 1554

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

#rationalize([eps]) ⇒ Object

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

# File 'rational.c', line 2141

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

#to_a ⇒ Object

call-seq:

   nil.to_a    -> []

Always returns an empty array.

   nil.to_a   #=> []

# File 'object.c', line 1357

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

#to_c ⇒ Object

Returns zero as a complex.

# File 'complex.c', line 1700

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

Returns:

• (0.0)

# File 'object.c', line 1327

static VALUE
nil_to_f(VALUE obj)
{
    return DBL2NUM(0.0);
}

#to_h ⇒ Object

call-seq:

   nil.to_h    -> {}

Always returns an empty hash.

   nil.to_h   #=> {}

# File 'object.c', line 1374

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

#to_i ⇒ 0

Always returns zero.

nil.to_i   #=> 0

Returns:

• (0)

# File 'object.c', line 1312

static VALUE
nil_to_i(VALUE obj)
{
    return INT2FIX(0);
}

#to_r ⇒ Object

Returns zero as a rational.

# File 'rational.c', line 2128

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

#to_s ⇒ Object

Always returns the empty string.

# File 'object.c', line 1340

static VALUE
nil_to_s(VALUE obj)
{
    return rb_cNilClass_to_s;
}

#| ⇒ Object