Extended maintenance of Ruby versions 1.8.7 and 1.9.2 ended on July 31, 2014. Read more

In Files

  • object.c

NilClass

The class of the singleton object nil.

Public Instance Methods

false & obj => false click to toggle source
nil & 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.

 
               static VALUE
false_and(obj, obj2)
    VALUE obj, obj2;
{
    return Qfalse;
}
            
false ^ obj => true or false click to toggle source
nil ^ obj => true or false

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

 
               static VALUE
false_xor(obj, obj2)
    VALUE obj, obj2;
{
    return RTEST(obj2)?Qtrue:Qfalse;
}
            
inspect => "nil" click to toggle source

Always returns the string “nil”.

 
               static VALUE
nil_inspect(obj)
    VALUE obj;
{
    return rb_str_new2("nil");
}
            
nil?() click to toggle source

call_seq:

nil.nil?               => true

Only the object nil responds true to nil?.

 
               static VALUE
rb_true(obj)
    VALUE obj;
{
    return Qtrue;
}
            
to_a => [] click to toggle source

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 click to toggle source

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 click to toggle source

Always returns zero.

nil.to_i   #=> 0
 
               static VALUE
nil_to_i(obj)
    VALUE obj;
{
    return INT2FIX(0);
}
            
to_s => "" click to toggle source

Always returns the empty string.

nil.to_s   #=> ""
 
               static VALUE
nil_to_s(obj)
    VALUE obj;
{
    return rb_str_new2("");
}
            
false | obj => true or false click to toggle source
nil | obj => true or false

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

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