javascript 字符串

String Search Methods
String indexOf()
String lastIndexOf()
String search()
See Also:
Basic String Methods
String Templates
String match()
String matchAll()
String includes()
String startsWith()
String endsWith()
https://www.w3schools.com/js/js_string_search.asp?goalId=721551e7-cf56-49ab-b572-83f2b5f8ee95