Trying to make a select filter with all the unique coins, but not getting to the end of it correctly.
When looping through data I can get a list of all the coins like this.
const uniqueCoins = data.map((item) => {
item.currencies.map((subItem) =>
console.log(subItem))
});
I also want to use the Set method and spread operator to get just unique values but I'm not sure how to combine all these.
const data = [
{
id: "1",
name: "Digitec",
description: "Wir akzeptieren folgende Kryptowährungen",
currencies: [
{coin: "Bitcoin"},
{coin: "Ethereum"},
{coin: "XRP"},
],
link: "webseite besuchen",
},
{
id: "2",
name: "Galaxus",
description: "Wir akzeptieren folgende Kryptowährungen",
currencies: [
{coin: "Bitcoin"},
{coin: "Monero"},
{coin: "XRP"},
],
link: "webseite besuchen",
},
{
id: "3",
name: "Brack.ch",
description: "Wir akzeptieren folgende Kryptowährungen",
currencies: [
{coin: "Litecoin"},
{coin: "Dogecoin"},
{coin: "XRP"},
],
link: "Onlineshop besuchen",
},
];
You can reduce the array and then remove the duplicates:
const uniqueCoins = [...new Set(data.reduce((prev, cur) => prev.concat(cur.currencies.map(cur => cur.coin)), []))]
Step 1 : Get all the coins in an array using array.reduce
const coins = data.reduce((prev, cur) => prev.concat(cur.currencies.map(cur => cur.coin)), []);
Step 2 : Remove all the uniques in the array
const uniqueCoins = [...new Set(coins)];
Start by combining all the coin values from all the currencies arrays using map, and flatMap, add that flattened array to a Set to dedupe the elements, and then spread the Set back out into an array.
const data=[{id:"1",name:"Digitec",description:"Wir akzeptieren folgende Kryptowährungen",currencies:[{coin:"Bitcoin"},{coin:"Ethereum"},{coin:"XRP"}],link:"webseite besuchen"},{id:"2",name:"Galaxus",description:"Wir akzeptieren folgende Kryptowährungen",currencies:[{coin:"Bitcoin"},{coin:"Monero"},{coin:"XRP"}],link:"webseite besuchen"},{id:"3",name:"Brack.ch",description:"Wir akzeptieren folgende Kryptowährungen",currencies:[{coin:"Litecoin"},{coin:"Dogecoin"},{coin:"XRP"}],link:"Onlineshop besuchen"}];
// Get a new array of coins for each object, and then
// flatten all of them into one array
const coins = data.flatMap(obj => {
return obj.currencies.map(currency => currency.coin);
});
// Create a set from the coins array
const set = new Set(coins);
// `sort and `map` over the array to produce
// an array of HTML for each option
const options = [...set].sort().map(option => {
return `<option value=${option}>${option}</option>`;
});
// Add those options to a select
const select = `
<select>
<option disabled selected>Choose a coin</option>
<option disabled>----</option>
${options.join('')}
</select>
`
// Add that HTML to a container
document.body.insertAdjacentHTML('beforeend', select);Additional documentation
Use .flatMap() method to get the coins sub-arrays and to flatten then array, then use new Set() to get unique values.
const data = [{id: "1",name: "Digitec",description: "Wir akzeptieren folgende Kryptowährungen",currencies: [{coin: "Bitcoin"},{coin: "Ethereum"},{coin: "XRP"}],link: "webseite besuchen"},{id: "2",name: "Galaxus",description: "Wir akzeptieren folgende Kryptowährungen",currencies: [{coin: "Bitcoin"},{coin: "Monero"},{coin: "XRP"}],link: "webseite besuchen"},{id: "3",name: "Brack.ch",description: "Wir akzeptieren folgende Kryptowährungen",currencies: [{coin: "Litecoin"},{coin: "Dogecoin"},{coin: "XRP"}],link: "Onlineshop besuchen"}];
const coins = [ ...new Set(
data.flatMap(({currencies}) => currencies.map(({coin}) => coin)))
];
console.log( coins );