search

The search() method searches for a match with a substring or a regular expression in a string and returns the index of the first occurrence found. If no match is found, it returns undefined.

Interactive example

Syntax

Classic signature

function search<
	GenericInput extends string
>(
	input: GenericInput, 
	pattern: string | RegExp
): number | undefined;

Curried signature

function search<
	GenericInput extends string
>(
	pattern: string | RegExp
): (input: GenericInput) => number | undefined;

Parameters

• input: The string in which to perform the search.
• pattern: The search pattern, which can be a string or a regular expression.

Return value

The index of the first occurrence of the pattern in the string, or undefined if no match is found.

See also

• indexOf: Returns the index of the first occurrence of a substring.
• lastIndexOf: Returns the index of the last occurrence of a substring.
• includes: Checks whether a string contains a substring.

Sources

• MDN Web Docs: String.prototype.search()