Checks if the given substring is present in the source string.

(search: string) => (text: string) => boolean

includes("brown fox")(
  "The quick brown fox jumps over the lazy dog",
);
// ⇒ true

Try in REPL

includes("brown dog")(
  "The quick brown fox jumps over the lazy dog",
);
// ⇒ false

Try in REPL