Converting an Array into object in Javascript

Question

I want to know the best way to convert an array in Js to object.

This is the sample of what i want to do. Input => ['abc', 'def']; Output => { abc: true, def: true }

I have done it using the code below. But just wanted to know if

**function toObject(strings) {
 var rv = {}
 strings.forEach(string => {
 rv[string] = true
 })
 return rv
}**

This function serves the purpose. But any experts out there with a best and efficient way possible.

• gurvinder372: strings.reduce( (a,c) => (a[c]=true, a), {})
• Aniket Sinha: Your function itself is good enough.

Answer 1

Not sure what you mean by best and efficient way possible, since yours is alright according to me, this is a less versbose version

var output = strings.reduce( (a,c) => (a[c]=true, a), {})

Demo

var strings = ['abc', 'def'];
var output = strings.reduce( (a,c) => (a[c]=true, a), {});
console.log(output);

• Prawal Sharma: "a[c]=true" - I understood this part. But can you please explain me the second part - ",a". All in all i want to know what this second parameter is doing after comma (a[c]=true, a). Is this assigning value in a.
• gurvinder372: That is the value returned by expression in () braces as output of every iteration. Please read up about reduce
• Prawal Sharma: Thanks for the reply. Now i understood it completely.

Answer 2

You could map single objects and assign it to the same object.

var array = ['abc', 'def'],
 object = Object.assign(...array.map(key => ({ [key]: true })));
 
console.log(object);

• gurvinder372: Nice, didn't thought of using Object.assign myself +1
• Prawal Sharma: Thanks for the quick reply. I also didn't gave a thought for this.