Method: Object#freeze

Defined in:
object.c

#freeze ⇒ Object

Prevents further modifications to obj. A RuntimeError will be raised if modification is attempted. There is no way to unfreeze a frozen object. See also Object#frozen?.

This method returns self.

a = [ "a", "b", "c" ]
a.freeze
a << "z"

produces:

prog.rb:3:in `<<': can't modify frozen array (RuntimeError)
	from prog.rb:3

Returns:



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# File 'object.c', line 1053

VALUE
rb_obj_freeze(VALUE obj)
{
    if (!OBJ_FROZEN(obj)) {
	OBJ_FREEZE(obj);
	if (SPECIAL_CONST_P(obj)) {
	    if (!immediate_frozen_tbl) {
		immediate_frozen_tbl = st_init_numtable();
	    }
	    st_insert(immediate_frozen_tbl, obj, (st_data_t)Qtrue);
	}
    }
    return obj;
}