Class: NilClass
Overview
The class of the singleton object nil
.
Instance Method Summary collapse
-
#& ⇒ Object
And—Returns
false
. -
#^ ⇒ Object
Exclusive Or—If obj is
nil
orfalse
, returnsfalse
; otherwise, returnstrue
. -
#inspect ⇒ Object
Always returns the string “nil”.
-
#nil? ⇒ true
Only the object nil responds
true
tonil?
. -
#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
Or—Returns
false
if obj isnil
orfalse
;true
otherwise.
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.
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# 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
.
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# File 'object.c', line 1333
static VALUE
false_xor(VALUE obj, VALUE obj2)
{
return RTEST(obj2)?Qtrue:Qfalse;
}
|
#inspect ⇒ Object
Always returns the string “nil”.
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# 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?
.
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# 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.
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# 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_a ⇒ Object
call-seq:
nil.to_a -> []
Always returns an empty array.
nil.to_a #=> []
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# File 'object.c', line 1152
static VALUE
nil_to_a(VALUE obj)
{
return rb_ary_new2(0);
}
|
#to_c ⇒ Object
Returns zero as a complex.
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# File 'complex.c', line 1512
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
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# File 'object.c', line 1122
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 #=> {}
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# File 'object.c', line 1169
static VALUE
nil_to_h(VALUE obj)
{
return rb_hash_new();
}
|
#to_i ⇒ 0
Always returns zero.
nil.to_i #=> 0
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# File 'object.c', line 1107
static VALUE
nil_to_i(VALUE obj)
{
return INT2FIX(0);
}
|
#to_r ⇒ Object
Returns zero as a rational.
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# File 'rational.c', line 1938
static VALUE
nilclass_to_r(VALUE self)
{
return rb_rational_new1(INT2FIX(0));
}
|
#to_s ⇒ Object
Always returns the empty string.
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# 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.
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# File 'object.c', line 1314
static VALUE
false_or(VALUE obj, VALUE obj2)
{
return RTEST(obj2)?Qtrue:Qfalse;
}
|