String Search

String Search

JavaScript offers several methods to search inside strings.

indexOf

Finds the first position of text, or -1 if not found:

"Hello World".indexOf("World"); // 6
"Hello World".indexOf("xyz");   // -1

Positions start at 0.

lastIndexOf

Finds the last position of text:

"a-b-c".lastIndexOf("-"); // 3

includes

Checks if text exists, returning a boolean:

"Hello".includes("ell"); // true

startsWith and endsWith

Check how a string begins or ends:

"Hello".startsWith("He"); // true
"Hello".endsWith("lo");   // true

search with patterns

search() works like indexOf but accepts regular expressions:

"Hello".search(/ell/); // 1

TL;DR

• indexOf returns the first position or -1.
• includes returns true/false.
• startsWith and endsWith check the edges.
• search accepts regular expressions.