JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = {
  23213: {
    customer: 'C',
    otherdata: 'foo'
  },
  643213: {
    customer: 'A',
    otherdata: 'bar'
  },
  1: {
    customer: 'D',
    otherdata: 'foobar'
  },
  2341: {
    customer: 'B',
    otherdata: 'barfoo'
  }
};

function iterate(data) {
  var arr = [];
  for (var prop in data) {
    if (data.hasOwnProperty(prop)) {
      var obj = {};
      obj[prop] = data[prop];
      obj.tempSortName = data[prop].customer.toLowerCase();
      arr.push(obj);
    }
  }
  arr.sort(function(a, b) {
    var at = a.tempSortName,
        bt = b.tempSortName;
    return at > bt ? 1 : ( at < bt ? -1 : 0 );
  });
  
  for (var i = 0, l = arr.length; i < l; i++) {
    var obj = arr[i];
    delete obj.tempSortName;
    console.log(obj);
    for (var prop in obj) {
      if (obj.hasOwnProperty(prop)) {
        var id = prop; //gets the obj "index" (id?)
      }
    }
    console.log(id);
    var item = obj[id];
    console.log(item.customer);
    //do stuff with item
  }
}

iterate(data);