判斷一個對象數組中某一項是否某一個值？

const data = [{
   name: "撤回",
   type: "withdraw"
}, {
   name: "...",
   type: "other",
   children: [{
      name: "會簽",
      type: "sign"
   }]
}];

const exist = data.some(item => item.type.indexOf('sign') > -1);

打印結果：

true