search() JavaScript String Method – How to Search a String

Whenever you use search() on a string, the method does the following:

1. It searches its calling string for the method’s regular expression argument.
2. 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 as String.prototype.search() because it is a method of the String object’s prototype 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 the new 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

Try Editing It

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

Try Editing It

Tip

• Suppose you need to start your search from a specific index. In that case, use indexOf().
• To do a global search for all matches, use match().