Arrange a JavaScript map based on its values and ensure that a specific field index remains at the top position

Question

Arrange a JavaScript map based on its values and ensure that a specific field index remains at the top position

I'm sure this question may seem simple to some, but as a JavaScript novice, I couldn't find the answer myself. Here is the code snippet I'm working with:

Let map = new Map<String,String>
map.set('0', select)
map.set('1', "foo");
map.set('2', "bar");
map.set('3', "baz");

My goal is to sort this map based on the values, with index 0 remaining at the top while sorting the rest. The desired output should look like this:

[{'0':'Select'},{'2':'bar'}, {'3':'baz'}, {'1': 'foo'}];

If anyone could assist me with this, I would greatly appreciate it.

javascript typescript

Answer 1

Answer №1

If you want to organize the map in a certain order, one approach is to retrieve the Map#entries and then sort the resulting array accordingly.

To prioritize a specific value at the top, or maintain it at the top, you can define a custom sort function for Array#sort that reflects the desired sorting criteria. In this scenario, the logic considers specific conditions to determine the order based on 'falsy' values like zero using the logical OR (||) operator.

let map = new Map();

map.set('0', "Select");
map.set('1', "foo");
map.set('2', "bar");
map.set('3', "baz");

result = Array.from(map).sort(([, a], [, b]) =>
    (b === 'Select') - (a === 'Select') || a.localeCompare(b)
);

console.log(result);

Answer 2

If you want to organize the map in a certain order, one approach is to retrieve the Map#entries and then sort the resulting array accordingly.

To prioritize a specific value at the top, or maintain it at the top, you can define a custom sort function for Array#sort that reflects the desired sorting criteria. In this scenario, the logic considers specific conditions to determine the order based on 'falsy' values like zero using the logical OR (||) operator.

let map = new Map();

map.set('0', "Select");
map.set('1', "foo");
map.set('2', "bar");
map.set('3', "baz");

result = Array.from(map).sort(([, a], [, b]) =>
    (b === 'Select') - (a === 'Select') || a.localeCompare(b)
);

console.log(result);

Arrange a JavaScript map based on its values and ensure that a specific field index remains at the top position

Answer №1

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