Write a function called longest which will take a string of space separated words and will return the longest one

longest.js

/*Write a function called longest which will take a string of space separated words and will return the longest one.

For example:

longest("This is Andela")
returns
"Andela"
and
longest("Brilliance is evenly distributed")
returns
distributed
*/

function longest(sentence){
  let str = sentence.split(" ");
    let longest = 0;
    let word = null;
    str.forEach(function(str) {
        if (longest < str.length) {
            longest = str.length;
            word = str;
        }
    });
    return word;
}