search() method of
String values executes a search for a match between a regular expression and this string, returning the index of the first match in the string.
The index of the first match between the regular expression and the given string, or
-1 if no match was found.
The implementation of
String.prototype.search() itself is very simple — it simply calls the
Symbol.search method of the argument with the string as the first parameter. The actual implementation comes from
g flag of
regexp has no effect on the
search() result, and the search always happens as if the regex's
lastIndex is 0. For more information on the behavior of
When you want to know whether a pattern is found, and also know its index within a string, use
The following example searches a string with two different regex objects to show a successful search (positive value) vs. an unsuccessful search (
const str = "hey JudE"; const re = /[A-Z]/; const reDot = /[.]/; console.log(str.search(re)); // returns 4, which is the index of the first capital letter "J" console.log(str.search(reDot)); // returns -1 cannot find '.' dot punctuation
|ECMAScript Language Specification |
BCD tables only load in the browser