code: function flattenArray(input, ans = {}) {
      if (!input || !Array.isArray(input)) return input || {}
      for (let k in input) {
          //recursive logic
          if (Array.isArray(input[k])) {
              ans = flattenArray(input[k], ans)
          } else {
              ans = Object.assign({}, ans, input[k])
          }
      }
      return ans
  }
docs: flatten deep array to plain object
  @param input may deep array,e.g. [{color:'red'},[{fontSize:11}]]
  @param ans output plain object,e,g. {color:'red',fontSize:11}
  @returns plain object mentioned above