动态编程：返回所有匹配数据

Question

I have written a simple dynamic program which can return first matched data. Now I want to get all matched data. My data :

let countryList = {
    country: [{
        name: "Bangladesh",
        province: [{
            name:"Dhaka",
            city: [{
                name:"Tangail",
                lat: '11'
            }, {
                name:"Jamalpur",
                lat: '12'
            }]
        }, {
            name: "Khulna",
            city: [{
                name:"Jossore",
                lat: '22'
            }, {
                name:"Tangail",
                lat: '23'
            }]
        }, {
            name: "Rajshahi",
            city: [{
                name:"Pabna",
                lat: '33'
            }, {
                name:"Rangpur",
                lat: '33'
            }]
        }]
    },{
        name: "India",
        province: [{
            name:"West Bengal",
            city: [{
                name:"Calcutta",
                lat: '111'
            }, {
                name:"Tangail",
                lat: '112'
            }]
        }, {
            name: "Uttar Pradesh",
            city: [{
                name:"Agra",
                lat: '122'
            }, {
                name:"Tajmahal",
                lat: '123'
            }]
        }, {
            name: "Rajasthan",
            city: [{
                name:"Kanpur",
                lat: '131'
            }, {
                name:"Jaypur",
                lat: '132'
            }]
        }]
    }]
}

Here I have two countries with provinces and cities. Here user can search any input like country, province or city. For example, for Tangail it should return all 3 result.

Expected Output:

[{
    name:"Tangail",
    lat: '11'
},{
    name:"Tangail",
    lat: '23'
}, {
    name:"Tangail",
    lat: '112'
}] 

I have tried as like as given below :

function findName(obj, name) {  return obj.name.trim() === name;  }

function information( countryList, searchValue, current, state ) {

   let nextState;  // state is used to prevent call of undefined data
   if ( state === "province" ) {
       nextState = "city";   current = "country";
   } else if( state === "city" ) {
       nextState = "empty";   current = "province";
   } else {
    nextState = "";  current = "city";
   }

   // search matching data
   let data = countryList.find( val => findName( val, searchValue ) );
   // if not data found
   if( typeof data === 'undefined' && nextState !== '' ) {
    let len = countryList.length;  
    for( let x = 0; x < len; x++ ) {  // now search all immediate child data
        let status = {};
        status.name = countryList[x].name;
        status.lebel = current;
        let info;
        info = information(countryList[x][state], searchValue, current, nextState);   // recursive call

        if( typeof info !== 'undefined' ) {  // if data found
            return {  state: status,  data: info };
        }
    }

    // return results;

   } else {
    return data;
   }
 }

let state = "province";
let current = "country";
let searchValue = "Tangail";
let abc = information( countryList.country, searchValue, current, state);
console.log("abc : ", abc);

And output is always first match value.

Any suggestion? Thanks in Advance.

NB: I'm using javascript

Answer 1

First convert into a list of cities using #reduce function - then filter using the search string from that array - see demo below:

 let countryList={country:[{name:"Bangladesh",province:[{name:"Dhaka",city:[{name:"Tangail",lat:"11"},{name:"Jamalpur",lat:"12"}]},{name:"Khulna",city:[{name:"Jossore",lat:"22"},{name:"Tangail",lat:"23"}]},{name:"Rajshahi",city:[{name:"Pabna",lat:"33"},{name:"Rangpur",lat:"33"}]}]},{name:"India",province:[{name:"West Bengal",city:[{name:"Calcutta",lat:"111"},{name:"Tangail",lat:"112"}]},{name:"Uttar Pradesh",city:[{name:"Agra",lat:"122"},{name:"Tajmahal",lat:"123"}]},{name:"Rajasthan",city:[{name:"Kanpur",lat:"131"},{name:"Jaypur",lat:"132"}]}]}]}; // convert into list of cities var cities = countryList.country.reduce(function(p,c){ c.province.forEach(function(e) { e.city.forEach(function(k){ p.push(k); }); }); return p; },[]); // filter based on the search string var result = cities.filter(function(e) { return e.name == 'Tangail'; }); console.log(result); 

 .as-console-wrapper{top:0;max-height:100%!important;} 

Answer 2

You could keep your style with the nested approach. But I suggest to use an object for the nested array properties and collect the wanted items in an array.

 function findName(obj, name) { return obj.name.trim() === name; } function information(object, key, search) { return object[key].reduce(function (r, o) { var temp = findName(o, search); if (temp) { r.push(o); return r; } if (states[key] && o[states[key]]) { return r.concat(information(o, states[key], search)); } return r; }, []); } var countryList = { country: [{ name: "Bangladesh", province: [{ name: "Dhaka", city: [{ name: "Tangail", lat: '11' }, { name: "Jamalpur", lat: '12' }] }, { name: "Khulna", city: [{ name: "Jossore", lat: '22' }, { name: "Tangail", lat: '23' }] }, { name: "Rajshahi", city: [{ name: "Pabna", lat: '33' }, { name: "Rangpur", lat: '33' }] }] }, { name: "India", province: [{ name: "West Bengal", city: [{ name: "Calcutta", lat: '111' }, { name: "Tangail", lat: '112' }] }, { name: "Uttar Pradesh", city: [{ name: "Agra", lat: '122' }, { name: "Tajmahal", lat: '123' }] }, { name: "Rajasthan", city: [{ name: "Kanpur", lat: '131' }, { name: "Jaypur", lat: '132' }] }] }] }, states = { country: 'province', province: 'city', city: '' }; console.log(information(countryList, 'country', 'Tangail')); 

 .as-console-wrapper { max-height: 100% !important; top: 0; }