Sort an array by string length within a function

Question

I have a problem that wants me to take an array of words, and return them in an array from smallest to largest word. This has to be done in a function. I have a simple form of it that is returning the results I desire:

//arr = ["Beg", "Life", "I", "To"]
//arr.sort(function(a, b){
//  return a.length - b.length;
//});

But I need to put it into a function. Here is what I have thus far with that part:

function sortByLength (array) {
    array.sort(function(a, b){
       return a.length - b.length;
    });
}
sortByLength(["Telescopes", "Glasses", "Eyes", "Monocles"]); 

I am not looking for the answer. Just some advice as to what I am doing wrong. Thanks for your help!

Answer 1

You can try this:

function sortByLength (array) {
   return array.sort((x,y) => x.length - y.length);
}

Answer 2

Looks like this works? If you set some variable to the sortByLength output is it right?

Answer 3

In your sortByLength function, you're not returning anything, so it's undefined. Consider putting a return just before the array.sort()

Answer 4

Yeah well just return the array. But as sorting sorts the passed array, it might be good to use .slice for copying it. Boiled down to an arrow func:

const sortByLength = arr => arr.slice().sort((a,b)=>a.length-b.length);

Or if you wanna do that faster ( maybe ) with a length table:

const sortByLength = arr => 
  arr.reduce((table,s)=> ( 
    (table[s.length] || (table[s.length] = [])).push(s), table), 
    []
  ).reduce((result, tablerow) => 
    result.concat(tablerow),
    []
);

Yup that ugly thing works ;)

Answer 5

You're not actually returning your value, you just need a return statement inside your sortByLength function:

 function sortByLength(array) { return array.sort(function(a, b) { return a.length - b.length; }); } console.log(sortByLength(["Telescopes", "Glasses", "Eyes", "Monocles"])); 

Edit : if you don't want to modify the original array, just add a slice() into the function and it will return a new array:

function sortByLength(array) {
  return array.slice().sort(function(a, b) {
    return a.length - b.length;
  });
}

var arrayOne = ["Telescopes", "Glasses", "Eyes", "Monocles"];
var arrayTwo = sortByLength(arrayOne);