Write a function, indexOf
, which takes in two strings--the needle and the haystack--and returns the index of the first appearance of the needle in the haystack. If the needle does not appear in the haystack, return -1
. Don't use indexOf()
, includes()
or substring()
,
indexOf('or', 'hello world'); // should return 7
indexOf('hello world', 'or'); // should return -1
indexOf('howdy', 'hello world'); // should return -1