How to work out which variable has the most characters using javascript

Question

How to work out which variable has the most characters.

For example :

var one = "qwert";
var two = "qwertyu"
var three ="qwertyuiop";

How to work out which variable has the most character.

First thing I am doing is counting the number of characters in each string.

var onelength = one.length;
var twolength = two.length;
var threelength = three.length;

The part I am struggling on is javascript to work out which of the above lengths has the most characters.

Answer 1

There's really no way to do this in Javascript (nor indeed in most languages).

What you're asking for is a kind of reflection. Conceptually, a function nameOfVariable that takes a variable and gives you it's string name in return:

nameOfVariable(one): 'one'

Not possible.

The answers above are attempts to work around that. Ultimately in real code this would be structured not as a bag of variables but as an object (which is kinda like a bag of variables, except you can recover the names)

const strings = {
  one: 'abcde',
  two: 'abcdef',
  three: 'abcd',
};
  
  
// Return key in object corresponding to longest string, 
// or null if object is empty.
const longest_string = strings => {
  let max = null;
  for (let name in strings) {
    if (max === null || strings[name].length > strings[max].length) {
      max = name;
    }
  }
  return max;
}

console.log(longest_string(strings));