Tuesday, November 27, 2018

JavaScript Array sort by several parameters

Array.prototype allows us to sort array just by 1 parameter. I have created my own method 'sortBy' to fix this gap. The method also allows to sort by desc. Let's say we have the following array
  
var objects = [{'Name': 'John', 'Age': 23, 'Profession': 'Accountant'},
    {'Name': 'Adam', 'Age': 18, 'Profession': 'Engineer'},
    {'Name': 'Vik', 'Age': 46, 'Profession': 'Architect'},
    {'Name': 'Jane', 'Age': 36, 'Profession': 'Developer'},
    {'Name': 'Rikky', 'Age': 28, 'Profession': 'Developer'}];
The following function call sorts the array by 'Profession' then by 'Name' descendantly
  
sortBy(objects, 'Profession', {'Name': 'desc'});
console.table(objects);
The result will be the following:

Now let's have a look at the method implementation.
  
var sortBy = function(arr, ...sortByArgs){
 arr.sort(function(a,b){
   var sortResult = 0;
   sortByArgs.forEach(function(arg){
     if (sortResult != 0) return;
      if(Object.values(arg)[0] == 'desc'){
        var propName = Object.keys(arg)[0];
       if (a[propName] > b[propName]){ 
       sortResult = -1;
       return;
       }
      if (a[propName] < b[propName]) {
       sortResult = 1;
        return;
       }
      }
      else {
     if (a[arg] < b[arg]){ 
       sortResult = -1;
       return;
       }
      if (a[arg] > b[arg]) {
       sortResult = 1;
        return;
       }
       }
    });
    
    return sortResult;
  });
};


You can try it on JSFiddler:
http://jsfiddle.net/AndrewBuntsev/cwt2gbej/
Don't forget to press F12 to display browser's console

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