I'm new to Javascript and was completing a training excerise. The problem is to return the highest outcome of the number of digits given.

Example: "678" should return 876.

Here's the code I wrote:

function max(n){  let r  = ("" n).split("")
  r.sort(function(a, b){return b-a});
  let result = r.join("")
return result;
}

I consoled out result to see if it did what I needed and would get '876' which I assumed was the correct but, would fail the test cases with response expected '876' to equal 876

I searched around and ending up finding a similar solution that added *1 at the end of join() like so:

let result = r.join("")*1

I'm having trouble understanding why I'd need that for it to be correct - Can someone help me understand why that would be necessary?

CodePudding user response：

r.join("")*1 coerces the result to a number instead of returning a string. It appears that the output of the function is being compared using strict equality to the expected result, which is also a number. Other methods to do this include using the unary plus operator (i.e., r.join("")), the Number function, and parseInt.