按其值对对象数组中的每个对象进行排序

Question

I have this function below to sort the keys of an object accordly their values.

var obj = {"A": 50, "B": 10, "C": 150 };

var ordered = Object.keys(obj).sort(function(a,b) {
            return obj[a] > obj[b] ? -1 :
                   obj[b] > obj[a] ? 1 : 0;
        });

console.log(ordered); // => [C, A, B];

However, when I have an Array of Objects, this function returns nothing.

For an Array of objects like this below:

var objs = [
    {"A": 50, "B": 10, "C": 150 },
    {"A": 60, "B": 100, "C": 10 },
    {"A": 150, "B": 100, "C": 30 } 
]

I have tried something like this:

let op =[];
objs.forEach((obj) => {
    let ordered = {};
     Object.keys(obj).sort().forEach((a,b) => {
      ordered = obj[a] > obj[b] ? -1 : obj[b] > obj[a] ? 1 : 0;
    });
  op.push(ordered);
});

console.log(op);

But this function returns an error: Identifier 'op' has already been declared.

I need to return something similar to the example above, but applied to each object. The result would be:

console.log(ordered); // => [[C, A, B], [B, A, C], [A, B, C]]

Answer 1

Cannot reproduce the error you describe, but here's another way to do it, using Object.entries() with some destructuring :

 const objs = [ {"A": 50, "B": 10, "C": 150 }, {"A": 60, "B": 100, "C": 10 }, {"A": 150, "B": 100, "C": 30 } ]; const ordered = objs.map(o => Object.entries(o) .sort(([k1, v1], [k2, v2]) => v2 - v1) .map(([k]) => k)); console.log(ordered);

Answer 2

In your code you are putting the sort logic in the forEach which isn't going to work. Since you already have a sort that works for you, to get your desired output, you can just make it a function and map it over the array:

 function ordered(obj) { return Object.keys(obj).sort(function(a, b) { return obj[a] > obj[b] ? -1 : obj[b] > obj[a] ? 1 : 0; }); } var objs = [ {"A": 50, "B": 10, "C": 150 }, {"A": 60, "B": 100, "C": 10 }, {"A": 150, "B": 100, "C": 30 } ] console.log(objs.map(ordered))

If you prefer the forEach code, you just need a couple changes:

 var objs = [ {"A": 50, "B": 10, "C": 150 }, {"A": 60, "B": 100, "C": 10 }, {"A": 150, "B": 100, "C": 30 } ] let op =[]; objs.forEach((obj) => { // just on forEach let ordered = Object.keys(obj).sort((a, b) => obj[a] > obj[b] ? -1 : obj[b] > obj[a] ? 1 : 0 // sort ) op.push(ordered); // push sorted array }); console.log(op);