my solution

Hello,

Could you please comment on my solution? it basically works, I have created it after the first video challange before the first solution, but after the first solution when we were asked to get rid of repeating code attached to red, green and blue variables i couldnot come up with an idea as in rgb synthax there are three numbers eg. rgb (xx, yy, zz) and all of them had to be randomly picked so I did nothing. After watching the solution I know I should have this instint of putting more complex things into variables, but perhaps You as more experienced developers will poin out some wrongs in my conception.

var html = '';
var red;
var green;
var blue;
var rgbColor;

function picker() {
    red = Math.floor(Math.random() * 256 );
    green = Math.floor(Math.random() * 256 );
    blue = Math.floor(Math.random() * 256 );
  return rgbColor = 'rgb(' + red + ',' + green + ',' + blue + ')';
}
for (let i=0; i<100; i+=1) {
html += '<div style="background-color:' + picker() + '"></div>';
}
document.write(html);

also one last question if I may, about this print function that Dave had written, I have tried it myself because I was curious if it would work when I leave the brackets empty, and I know by now that it would not, and that there have to be anything as long as it matches what is inside the document.write brackets eg:

function print(x) {
document.write(x);
}
print(html);

so this x a kind of declaration of some sort? Why can we not leave it empty? Sorry if that do not make any sense but I dont feel quite comfortable with the topic and I am trying to grasp the conception.