search() JavaScript String Method – How to Search a String
Whenever you use search() on a string, the method does the following:
- It searches its calling string for the method's regular expression argument.
- It returns the index of the first match, or
-1
if the RegExp pattern found no match.
note
- A calling string is a string on which you used
search()
. So, in"Hello, world!".search("world")
,"Hello, world!"
is the calling string. search()
is sometimes written asString.prototype.search()
because it is a method of theString
object'sprototype
property.
Syntax of the search()
Method
search()
accepts a regular expression argument. Here is the syntax:
callingString.search(RegExp);
note
- Suppose
search()
's argument is a non-RegExp
value—such as a string or a number. In that case, JavaScript will use thenew RegExp(...)
syntax to convert the argument to a regular expression. 0
returns if you do not provide an argument.
Example 1: Search for day
"SunDay, Tuesday, and Friday are good DAYS".search(/day/);
// The invocation above will return: 12
Example 2: Search for a Case-Insensitive day
Pattern
"SunDay, Tuesday, and Friday are good DAYS".search(/day/i);
// The invocation above will return: 3
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Overview
search()
searches its calling string for the first occurrence of the method's regular expression argument.