check type

is.js

function isString(target) {
  return isType(target, 'String')
}

function isNumber(target) {
  return isType(target, 'Number')
}

function isDate(target) {
  return isType(target, 'Date')
}

function isFunction(target) {
  return isType(target, 'Function')
}

function isObject(target) {
  return isType(target, 'Object')
}

function isArray(target) {
  return isType(target, 'Array')
}

function isType(target, type) {
  return Object.prototype.toString.call(target) === `[object ${type}]` ? true : false
}