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JavaScript Search

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The JavaScript Search method is used to search and return the index position of the first occurrence of a specified string in a regular expression search. JavaScript Search will return -1, if the specified string is not found.

In this article we will show you, How to write Search() Function in JavaScript with example.

TIP: The index position in Search() Function will start from 0, Not 1.

JavaScript Search Syntax

The basic syntax of the JavaScript Search function is as shown below:

String_Object.Search(RegExp)

String_Object: Please select the valid String Object or literal.

RegExp: The search value can be a String or Regular Expression.

JavaScript Search Example

The following set of examples will help you understand the JavaScript Search Function.

JAVASCRIPT CODE

<!DOCTYPE html>
<html>
<head>
    <title> JavaScript Search </title>
</head>
<body>
    <h1> JavaScript Search </h1>
<script>
  var Str1 = "Learn JavaScript at Tutorial Gateway.org";
  var Str2 = "We are ABC working at abc company";
 
  var Str3 = Str1.search("Script");
  var Str4 = Str1.search("abc"); // Non existing item
  var Str5 = Str2.search("abc");
  var Str6 = Str2.search(/abc/i);

  document.write("<b> Index position of Script is:</b> " + Str3);
  document.write("<br \> <b> Index position of abc is:</b> " + Str4);
  document.write("<br \> <b> Index position of abc is:</b> " + Str5);
  document.write("<br \> <b> Index position of abc is:</b> " + Str6);
</script>
</body>
</html>

OUTPUT

JavaScript Search

ANALYSIS

In this JavaScript Search function example, within the Script tag, First we declared two String variables Str1, Str2 and assigned corresponding values using following statement

 var Str1 = "Learn JavaScript at Tutorial Gateway.org";
 var Str2 = "We are abc working at abc company";

Following statement will search for the index position of a substring “Script” and store the index value in Str3.

var Str3 = Str1.search("Script");

NOTE: You should count the space as One Character.

In the next line we are searching for non existing item “abc” inside the Str1. Since Search() function doesn’t find the substring, it is returning -1 as output

 var Str4 = Str1.search("abc"); // Non existing item

In the next line we are looking for “abc” inside the Str2.

 var Str5 = Str2.search("abc");

From the above statement you can observe that, although term abc is repeated multiple times, JavaScript Search() function consider the string “ABC” is different from “abc”. Now, let us use the i regular expression along with string

var Str6 = Str2.search(/abc/i);

Above statement will perform the case insensitive string search So, Search() function will return the index position of first occurrence i.e., ABC.

Following statements will write the content output to the respective browser

  document.write("<b> Index position of Script is:</b> " + Str3);
  document.write("<br \> <b> Index position of abc is:</b> " + Str4);
  document.write("<br \> <b> Index position of abc is:</b> " + Str5);
  document.write("<br \> <b> Index position of abc is:</b> " + Str6);

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