Class: NilClass

Inherits:
Object show all
Defined in:
object.c,
object.c

Overview

The class of the singleton object nil.

Instance Method Summary collapse

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)

1217
1218
1219
1220
1221
# File 'object.c', line 1217

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

#^(obj) ⇒ Boolean #^(obj) ⇒ Boolean

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

Overloads:

  • #^(obj) ⇒ Boolean

    Returns:

    • (Boolean)
  • #^(obj) ⇒ Boolean

    Returns:

    • (Boolean)

1252
1253
1254
1255
1256
# File 'object.c', line 1252

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

#inspectObject

Always returns the string "nil".


1101
1102
1103
1104
1105
# File 'object.c', line 1101

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

#nil?Boolean

call_seq:

nil.nil?               -> true

Only the object nil responds true to nil?.

Returns:

  • (Boolean)

1265
1266
1267
1268
1269
# File 'object.c', line 1265

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

#rationalize([eps]) ⇒ Object

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


1853
1854
1855
1856
1857
1858
# File 'rational.c', line 1853

static VALUE
nilclass_rationalize(int argc, VALUE *argv, VALUE self)
{
    rb_scan_args(argc, argv, "01", NULL);
    return nilclass_to_r(self);
}

#to_aObject

call-seq:

   nil.to_a    -> []

Always returns an empty array.

   nil.to_a   #=> []

1071
1072
1073
1074
1075
# File 'object.c', line 1071

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

#to_cObject

Returns zero as a complex.


1497
1498
1499
1500
1501
# File 'complex.c', line 1497

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

#to_f0.0

Always returns zero.

nil.to_f   #=> 0.0

Returns:

  • (0.0)

1041
1042
1043
1044
1045
# File 'object.c', line 1041

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

#to_hObject

call-seq:

   nil.to_h    -> {}

Always returns an empty hash.

   nil.to_h   #=> {}

1088
1089
1090
1091
1092
# File 'object.c', line 1088

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

#to_i0

Always returns zero.

nil.to_i   #=> 0

Returns:

  • (0)

1026
1027
1028
1029
1030
# File 'object.c', line 1026

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

#to_rObject

Returns zero as a rational.


1840
1841
1842
1843
1844
# File 'rational.c', line 1840

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

#to_sObject

Always returns the empty string.


1054
1055
1056
1057
1058
# File 'object.c', line 1054

static VALUE
nil_to_s(VALUE obj)
{
    return rb_usascii_str_new(0, 0);
}

#|(obj) ⇒ Boolean #|(obj) ⇒ Boolean

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

Overloads:

  • #|(obj) ⇒ Boolean

    Returns:

    • (Boolean)
  • #|(obj) ⇒ Boolean

    Returns:

    • (Boolean)

1233
1234
1235
1236
1237
# File 'object.c', line 1233

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