fl_name 全天房费率is_selected 0_id 3yb2pa0hfkxffl_name 半天房费率is_selected 1_id 3yb2pa0hfkxdjs查找数组中is_selected==1的_id

可以使用Array.prototype.find方法来查找数组中满足条件的元素。下面是一个示例代码：

const arr = [
  {fl_name: "全天房费率",is_selected: 0,_id: "3yb2pa0hfkxf"},
  {fl_name: "半天房费率",is_selected: 1,_id: "3yb2pa0hfkxd"}
];

const selectedId = arr.find(item => item.is_selected === 1)._id;
console.log(selectedId);

输出结果为3yb2pa0hfkxd，即满足条件is_selected==1的元素的_id值。