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)

1298
1299
1300
1301
1302
# File 'object.c', line 1298

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)

1333
1334
1335
1336
1337
# File 'object.c', line 1333

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

#inspectObject

Always returns the string “nil”.


1182
1183
1184
1185
1186
# File 'object.c', line 1182

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

#nil?true

Only the object nil responds true to nil?.

Returns:

  • (true)

Returns:

  • (Boolean)

1346
1347
1348
1349
1350
# File 'object.c', line 1346

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

#rationalize([eps]) ⇒ Object

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


1951
1952
1953
1954
1955
1956
# File 'rational.c', line 1951

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   #=> []

1152
1153
1154
1155
1156
# File 'object.c', line 1152

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

#to_cObject

Returns zero as a complex.


1512
1513
1514
1515
1516
# File 'complex.c', line 1512

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)

1122
1123
1124
1125
1126
# File 'object.c', line 1122

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   #=> {}

1169
1170
1171
1172
1173
# File 'object.c', line 1169

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

#to_i0

Always returns zero.

nil.to_i   #=> 0

Returns:

  • (0)

1107
1108
1109
1110
1111
# File 'object.c', line 1107

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

#to_rObject

Returns zero as a rational.


1938
1939
1940
1941
1942
# File 'rational.c', line 1938

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

#to_sObject

Always returns the empty string.


1135
1136
1137
1138
1139
# File 'object.c', line 1135

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)

1314
1315
1316
1317
1318
# File 'object.c', line 1314

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