Class: NilClass

Inherits:
Object show all
Defined in:
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) 



# File 'object.c'

/*
 *  call-seq:
 *     false & obj   => false
 *     nil & obj     => false
 *  
 *  And---Returns <code>false</code>. <i>obj</i> is always
 *  evaluated as it is the argument to a method call---there is no
 *  short-circuit evaluation in this case.
 */

static VALUE
false_and(obj, obj2)
    VALUE obj, 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) 



# File 'object.c'

/*
 *  call-seq:
 *     false ^ obj    => true or false
 *     nil   ^ obj    => true or false
 *  
 *  Exclusive Or---If <i>obj</i> is <code>nil</code> or
 *  <code>false</code>, returns <code>false</code>; otherwise, returns
 *  <code>true</code>.
 *     
 */

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

#inspect ⇒ Object

Always returns the string "nil".




# File 'object.c'

/*
 *  call-seq:
 *    nil.inspect  => "nil"
 *
 *  Always returns the string "nil".
 */

static VALUE
nil_inspect(obj)
    VALUE obj;
{
    return rb_str_new2("nil");
}

#nil? ⇒ Object

call_seq:

nil.nil?               => true

Only the object nil responds true to nil?.




# File 'object.c'

/*
 * call_seq:
 *   nil.nil?               => true
 *
 * Only the object <i>nil</i> responds <code>true</code> to <code>nil?</code>.
 */

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

#to_a ⇒ Array

Always returns an empty array.

nil.to_a   #=> []

Returns:




# File 'object.c'

/*
 *  call-seq:
 *     nil.to_a    => []
 *  
 *  Always returns an empty array.
 *     
 *     nil.to_a   #=> []
 */

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

#to_f ⇒ 0.0

Always returns zero.

nil.to_f   #=> 0.0

Returns:

  • (0.0) 



# File 'object.c'

/*
 *  call-seq:
 *     nil.to_f    => 0.0
 *  
 *  Always returns zero.
 *     
 *     nil.to_f   #=> 0.0
 */

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

#to_i ⇒ 0

Always returns zero.

nil.to_i   #=> 0

Returns:

  • (0) 



# File 'object.c'

/*
 *  call-seq:
 *     nil.to_i => 0
 *  
 *  Always returns zero.
 *     
 *     nil.to_i   #=> 0
 */


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

#to_s ⇒ Object

Always returns the empty string.

nil.to_s   #=> ""




# File 'object.c'

/*
 *  call-seq:
 *     nil.to_s    => ""
 *  
 *  Always returns the empty string.
 *     
 *     nil.to_s   #=> ""
 */

static VALUE
nil_to_s(obj)
    VALUE obj;
{
    return rb_str_new2("");
}

#|(obj) ⇒ Boolean #|(obj) ⇒ Boolean

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

Overloads:

  • #|(obj) ⇒ Boolean

    Returns:

    • (Boolean)
  • #|(obj) ⇒ Boolean

    Returns:

    • (Boolean) 



# File 'object.c'

/*
 *  call-seq:
 *     false | obj   =>   true or false
 *     nil   | obj   =>   true or false
 *  
 *  Or---Returns <code>false</code> if <i>obj</i> is
 *  <code>nil</code> or <code>false</code>; <code>true</code> otherwise.
 */

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