Language GuideBuilt-in TypesArrayMethodsfind_last_indexOn this pagefind_last_indexFind the index of the last element based on the test. [3,1,2,3].find_last_index((thisElement) => thisElement === 3); // returns 3u Syntax find_last_index(callback) Returns The last found value's index as uint. An undefined when nothing is found. Notes The callback is expected to contain ONE parameter.