Object#instance_variable_set

[T] (::interned variable, T value) -> T

obj.instance_variable_set(symbol, obj) → obj

obj.instance_variable_set(string, obj) → obj

static VALUE
rb_obj_ivar_set_m(VALUE obj, VALUE iv, VALUE val)
{
    ID id = id_for_var(obj, iv, instance);
    if (!id) id = rb_intern_str(iv);
    return rb_ivar_set(obj, id, val);
}

Sets the instance variable named by symbol to the given object. This may circumvent the encapsulation intended by the author of the class, so it should be used with care. The variable does not have to exist prior to this call. If the instance variable name is passed as a string, that string is converted to a symbol.

Example

class Fred
  def initialize(p1, p2)
    @a, @b = p1, p2
  end
end
fred = Fred.new('cat', 99)
fred.instance_variable_set(:@a, 'dog')   #=> "dog"
fred.instance_variable_set(:@c, 'cat')   #=> "cat"
fred.inspect                             #=> "#<Fred:0x401b3da8 @a=\"dog\", @b=99, @c=\"cat\">"

See also #instance_variables #is_a? #instance_variable_get #itself also in 4.1 · 4.0 · 3.3 · 3.2 · 3.1 · 3.0

‹ prev#instance_variables next ›#is_a?