I have some objects
var officers = [
{ id: 20, name: 'Captain Piett' },
{ id: 24, name: 'General Veers' },
{ id: 56, name: 'Admiral Ozzel' },
{ id: 88, name: 'Commander Jerjerrod' }
];
I need to return "20","24","56","88"
Now I'm using
const ids = officers.map(officer => officer.id);
but it return me an array of course.
What's the most efficient way?
You can use map() to return array of string with "" and then use join()
var officers = [
{ id: 20, name: 'Captain Piett' },
{ id: 24, name: 'General Veers' },
{ id: 56, name: 'Admiral Ozzel' },
{ id: 88, name: 'Commander Jerjerrod' }
];
const res = officers.map(x => `"${x.id}"`).join()
console.log(res)You can surround by quotes on map and then call Array.join.
const ids = officers.map(officer => '"' + officer.id + '"').join();
What's the most efficient way?
Array.map creates each time a new function and calls it, thats not efficient.
The most efficient way is to use plain for-loops:
var res = '';
for(let {id} in officers){
res+=....
}
But now you would create each time a new string (res+=...).
Thats absolutely ok if you don't have to handle alot of strings, but in the case you do you may want to switch to arrays and join it into a string at the end.
