TypeScript typeof utility helper with no dependencies. Provides type guards for all common types.

npm install ts-util-is

Import everything:

import * as util from 'ts-util-is';

const value: string | string[] = 'hey there';

if (util.isArray(value)) {
  console.log(value.split(' ')); // `value` is string[]
}

Import only what you need:

import { isArray, isString } from 'ts-util-is';

const value: string | string[] = 'hello again';

if (isArray(value)) {
  console.log(value.split(' ')); // `value` is string
}

• isArray()
• isBase64()
• isBoolean()
• isDate()
• isDateValid()
• isDefined()
• isError()
• isFunction()
• isGuid()
• isInfinity()
• isNegativeNumber()
• isNull()
• isNil()
• isNonEmptyString()
• isNonZeroNumber()
• isNumber()
• isObject()
• isPlainObject()
• isPositiveNumber()
• isRegExp()
• isString()
• isSymbol()
• isUndefined()
• isInstance()