--TEST-- ZE2 An interface is inherited --SKIPIF-- --FILE-- _is_a('base'); echo $this->_is_a('derived_a'); echo $this->_is_a('derived_b'); echo $this->_is_a('derived_c'); echo $this->_is_a('derived_d'); echo $this->_is_a('if_a'); echo $this->_is_a('if_b'); echo "\n"; } } class derived_a extends base implements if_a { function f_a() {} } class derived_b extends base implements if_a, if_b { function f_a() {} function f_b() {} } class derived_c extends derived_a implements if_b { function f_b() {} } class derived_d extends derived_c { } $t = new base(); $t->test(); $t = new derived_a(); $t->test(); $t = new derived_b(); $t->test(); $t = new derived_c(); $t->test(); $t = new derived_d(); $t->test(); ?> --EXPECTF-- is_a(base, base) = yes is_a(base, derived_a) = no is_a(base, derived_b) = no is_a(base, derived_c) = no is_a(base, derived_d) = no is_a(base, if_a) = no is_a(base, if_b) = no is_a(derived_a, base) = yes is_a(derived_a, derived_a) = yes is_a(derived_a, derived_b) = no is_a(derived_a, derived_c) = no is_a(derived_a, derived_d) = no is_a(derived_a, if_a) = yes is_a(derived_a, if_b) = no is_a(derived_b, base) = yes is_a(derived_b, derived_a) = no is_a(derived_b, derived_b) = yes is_a(derived_b, derived_c) = no is_a(derived_b, derived_d) = no is_a(derived_b, if_a) = yes is_a(derived_b, if_b) = yes is_a(derived_c, base) = yes is_a(derived_c, derived_a) = yes is_a(derived_c, derived_b) = no is_a(derived_c, derived_c) = yes is_a(derived_c, derived_d) = no is_a(derived_c, if_a) = yes is_a(derived_c, if_b) = yes is_a(derived_d, base) = yes is_a(derived_d, derived_a) = yes is_a(derived_d, derived_b) = no is_a(derived_d, derived_c) = yes is_a(derived_d, derived_d) = yes is_a(derived_d, if_a) = yes is_a(derived_d, if_b) = yes