isObjectEqual (a, b) {
    // 獲取a、b的型別
    var classNameA = toString.call(a)
    var classNameB = toString.call(b)

    if (classNameA === '[object Object]' && classNameB === '[object Object]') {
      var propsA = Object.getOwnPropertyNames(a)
      var propsB = Object.getOwnPropertyNames(b)
      if
 
 (propsA.length !== propsB.length) {
        return false
      }
      for (let i = 0; i < propsA.length; i++) {
        var propName = propsA[i]
        if (a[propName] !== b[propName]) {
          return false
        }
      }
      return true
    }
}