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) 


1303
1304
1305
1306
1307
 
# File 'object.c', line 1303

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) 


1338
1339
1340
1341
1342
 
# File 'object.c', line 1338

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

#inspect ⇒ Object

Always returns the string “nil”.



1187
1188
1189
1190
1191
 
# File 'object.c', line 1187

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) 


1351
1352
1353
1354
1355
 
# File 'object.c', line 1351

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

#rationalize([eps]) ⇒ Object

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



1934
1935
1936
1937
1938
1939
 
# File 'rational.c', line 1934

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

#to_a ⇒ Object

call-seq:

   nil.to_a    -> []

Always returns an empty array.

   nil.to_a   #=> []



1157
1158
1159
1160
1161
 
# File 'object.c', line 1157

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

#to_c ⇒ Object

Returns zero as a complex.



1477
1478
1479
1480
1481
 
# File 'complex.c', line 1477

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) 


1127
1128
1129
1130
1131
 
# File 'object.c', line 1127

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   #=> {}



1174
1175
1176
1177
1178
 
# File 'object.c', line 1174

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

#to_i ⇒ 0

Always returns zero.

nil.to_i   #=> 0

Returns:

  • (0) 


1112
1113
1114
1115
1116
 
# File 'object.c', line 1112

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

#to_r ⇒ Object

Returns zero as a rational.



1921
1922
1923
1924
1925
 
# File 'rational.c', line 1921

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

#to_s ⇒ Object

Always returns the empty string.



1140
1141
1142
1143
1144
 
# File 'object.c', line 1140

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) 


1319
1320
1321
1322
1323
 
# File 'object.c', line 1319

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