Question

我的密钥标识符看起来像这样......

const category = key; // could be "bus","car","plane"

对于此示例，请使用"bus"。我还有一个看起来像这样的字符串数组......

let transportationFields = [
      'bus_station', 'bus_stop', 'bus_line', 'took_bus'
      'car', 'buyer_of_car', 'car_model',
      'train_number', 'train_trip_num', 'train_stop',
    ];

现在我抓住了

的索引

const transFieldValues = transportationFields.indexOf(category) > -1;

但这只会返回true。我怎样才能抓住它匹配的字段？例如。自category = bus起。我怎样才能归还所有真实值？（'bus_station', 'bus_stop', 'bus_line', 'took_bus'）？

提前感谢您的帮助！

Answer 1

您可以使用.filter()查找所有匹配项并将其返回到数组中：

＆＃13;

let transportationFields = [
  'bus_station', 'bus_stop', 'bus_line', 'took_bus',
  'car', 'buyer_of_car', 'car_model',
  'train_number', 'train_trip_num', 'train_stop',
];

let category = 'bus';

let transFieldValues = transportationFields.filter(function (item) {
  return item.indexOf(category) > -1;
});

document.write (JSON.stringify(transFieldValues));

＆＃13;

或使用ES6箭头功能：

＆＃13;

let transportationFields = [
  'bus_station', 'bus_stop', 'bus_line', 'took_bus',
  'car', 'buyer_of_car', 'car_model',
  'train_number', 'train_trip_num', 'train_stop',
];

let category = 'bus';

let transFieldValues = transportationFields.filter(w => w.indexOf(category) > -1);

document.write (JSON.stringify(transFieldValues));

＆＃13;

如果您不介意让Edge用户失去运气，那么您可以使用.includes()：

let transFieldValues = transportationFields.filter(w => w.includes(category));

...看起来比你> -1使用的.indexOf()更好。

Answer 2

您可以使用Array#filter

＆＃13;

let transportationFields = [
  'bus_station', 'bus_stop', 'bus_line', 'took_bus',
  'car', 'buyer_of_car', 'car_model',
  'train_number', 'train_trip_num', 'train_stop',
];

transportationFields = transportationFields.filter(e => {
  return e.indexOf('bus') != -1;
});

console.log(transportationFields)

＆＃13;

您还可以创建一个函数并将值传递给搜索

＆＃13;

let transportationFields = ['bus_station', 'bus_stop', 'bus_line', 'took_bus','car', 'buyer_of_car', 'car_model','train_number', 'train_trip_num', 'train_stop'];

var findField = function(input) {
  return transportationFields.filter(e => {return e.indexOf(input) != -1;});
}

console.log(findField('bus'));

＆＃13;

检查数组中是否存在字符串值并返回找到的数组值js

2 个答案: