/*--------------------------------------------------------------------------------------------- * Copyright (c) Microsoft Corporation. All rights reserved. * Licensed under the MIT License. See License.txt in the project root for license information. *--------------------------------------------------------------------------------------------*/ export function startsWith(haystack: string, needle: string): boolean { if (haystack.length < needle.length) { return false; } for (let i = 0; i < needle.length; i++) { if (haystack[i] !== needle[i]) { return false; } } return true; } /** * Determines if haystack ends with needle. */ export function endsWith(haystack: string, needle: string): boolean { let diff = haystack.length - needle.length; if (diff > 0) { return haystack.lastIndexOf(needle) === diff; } else if (diff === 0) { return haystack === needle; } else { return false; } }