Javascript 一个数组的匹配对象

Question

I have this array, I wish to pick out all the names which have a URL which contains '/blekinge'.

Any way to do this with map? And present in a list? I've come this far:

const allaOrter = orter.map((allOrt) =>
<li>{allOrt.url}</li>
)

What I would like to do is to have sort of an ifstatement or a forEach loop that picks out all the URLs which contains /blekinge and present those. But I dont know how... The real array I'm working with is much bigger and contains loads of urls. Maybe even make new arrays which contains those elements that have a common url. I hope my provided example is enough for someone of you guys to help me out. :)

orter.json
[{
        "id": "2",
        "namn": "Blekinge",
        "url": "/blekinge"
    },
    {
        "id": "23",
        "namn": "Karlshamn",
        "url": "/blekinge/karlshamn"
    },
    {
        "id": "24",
        "namn": "Karlskrona",
        "url": "/blekinge/karlskrona"
    },
    {
        "id": "25",
        "namn": "Olofström",
        "url": "/blekinge/olofstrom"
    },
    {
        "id": "26",
        "namn": "Ronneby",
        "url": "/blekinge/ronneby"
    }]

Answer 1

Use array.prototype.filter method then map the returned array

const arr = [{
        "id": "2",
        "namn": "Blekinge",
        "url": "/blekinge"
    },
    {
        "id": "23",
        "namn": "Karlshamn",
        "url": "/blekinge/karlshamn"
    },
    {
        "id": "24",
        "namn": "Karlskrona",
        "url": "/blekinge/karlskrona"
    },
    {
        "id": "25",
        "namn": "Olofström",
        "url": "/blekinge/olofstrom"
    },
    {
        "id": "26",
        "namn": "Ronneby",
        "url": "/blekinge/ronneby"
    }]
    
let filtered = (a) => a.url.includes("/blekinge")


console.log(arr.filter(filtered))

then map the result

Answer 2

You should first try to narrow down by matching the object which contains the url /blekinge using the filter method. Once you have filtered, the resulting array can be used to present a list.

To keep things simple, I implemented an unordered list to present the result, but the core of what you need is in the resulting filtered array.

 let listElement = document.getElementById('name-list'); let data = [ { "id": "2", "name": "Blekinge", "url": "/blekinge" }, { "id": "23", "name": "Karlshamn", "url": "/blekinge/karlshamn" }, { "id": "24", "name": "Karlskrona", "url": "/blekinge/karlskrona" }, { "id": "25", "name": "Olofström", "url": "/blekinge/olofstrom" }, { "id": "26", "name": "Ronneby", "url": "/test/ronneby" } ]; let updateList = (list, content) => { let li = document.createElement("li"); li.innerHTML = content; list.appendChild(li); }; let filteredData = data.filter(elem => elem.url.indexOf('/blekinge');== -1). filteredData,map(elem => updateList(listElement. elem;name));

 <label for="name-list">Matching names</label> <ul id="name-list"> <ul>

Answer 3

Working Demo:

 const data = [{ "id": "2", "namn": "Blekinge", "url": "/blekinge" }, { "id": "23", "namn": "Karlshamn", "url": "/alpha/beta" }, { "id": "24", "namn": "Karlskrona", "url": "/blekinge/karlskrona" }, { "id": "25", "namn": "Olofström", "url": "/abc/def" }, { "id": "26", "namn": "Ronneby", "url": "/blekinge/ronneby" }]; const res = data.filter((obj) => obj.url.indexOf('/blekinge');== -1). console;log(res);