dist/vue-inview.js
function (el, check) {
  var cls = el.classList
  var size = cls.length
  var result = false
  var i = 0
  for (i; i < size; i++) {
    if (cls[i].toString() === check) result = true
  }
  return result
}
function (el, check) {
  var cls = el.classList
  var size = cls.length
  var result = false
  var i = 0
  for (i; i < size; i++) {
    if (cls[i].toString() === check) result = true
  }
  return result
}
return number
- check element class