Top values in the object, displayed with keys, javascript

Question

I'm able to successfuly find out the largest values in the object, however. There is a problem, and that is inability to display the associated key with that value.

var obj = {
    t1: 1,
    t2: 33,
    t3: 10,
    t4: 9,
    t5: 45,
    t6: 101
    //...
}

// create an array
var arr = [];

// loop through the object and add values to the array
for (var p in obj) {
  arr.push(obj[p]);
}

// sort the array, largest numbers to lowest
arr.sort(function(a,b){return b - a});

// grab the first 10 numbers
var firstThree = arr.slice(0, 3);
console.log(firstThree);

It can display the top values, however i'm having a hard time to display keys with that.

The result should be like

var result = {
    t6: 101,
    t5: 45,
    t2: 33

}

Answer 1

You could get the entries, sort and slice them and build a new object by assigning mapped objects to a single object.

var object = { t1: 1, t2: 33, t3: 10, t4: 9, t5: 45, t6: 101 },
    result = Object.assign(                      // collect all objects into a single obj
        ...Object                                // spread the final array as parameters
            .entries(object)                     // key a list of key/ value pairs
            .sort(({ 1: a }, { 1: b }) => b - a) // sort DESC by index 1
            .slice(0, 3)                         // get first three items of array
            .map(([k, v]) => ({ [k]: v }))       // map an object with a destructured
    );                                           // key/value pair

console.log(result);