method

const_defined?

v1_9_3_392 - Show latest stable - Class: Module

const_defined?(p1, p2 = v2)

public

Checks for a constant with the given name in mod If inherit is set, the lookup will also search the ancestors (and Object if mod is a Module.)

Returns whether or not a definition is found:

Math.const_defined? "PI"   #=> true
IO.const_defined? :SYNC   #=> true
IO.const_defined? :SYNC, false   #=> false

static VALUE
rb_mod_const_defined(int argc, VALUE *argv, VALUE mod)
{
    VALUE name, recur;
    ID id;

    if (argc == 1) {
        name = argv[0];
        recur = Qtrue;
    }
    else {
        rb_scan_args(argc, argv, "11", &name, &recur);
    }
    id = rb_to_id(name);
    if (!rb_is_const_id(id)) {
        rb_name_error(id, "wrong constant name %s", rb_id2name(id));
    }
    return RTEST(recur) ? rb_const_defined(mod, id) : rb_const_defined_at(mod, id);
}

const_defined?

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