Skip to main content
Using Deno in production at your company? Earn free Deno merch.
Give us feedback
Module

std/bytes/starts_with.ts

The Deno Standard Library
Latest
File
// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Returns `true` if the prefix array appears at the start of the source array, * `false` otherwise. * * The complexity of this function is `O(prefix.length)`. * * @param source Source array to check. * @param prefix Prefix array to check for. * @returns `true` if the prefix array appears at the start of the source array, * `false` otherwise. * * @example Basic usage * ```ts * import { startsWith } from "https://deno.land/std@$STD_VERSION/bytes/starts_with.ts"; * * const source = new Uint8Array([0, 1, 2, 1, 2, 1, 2, 3]); * const prefix = new Uint8Array([0, 1, 2]); * * startsWith(source, prefix); // true * ``` */export function startsWith(source: Uint8Array, prefix: Uint8Array): boolean { for (let i = 0; i < prefix.length; i++) { if (source[i] !== prefix[i]) return false; } return true;}