不能填充数组

function draw(data)
{
var i = 0;
var checkduplicates = new Array();
drawOne(i);
//console.log(checkduplicates) Problem!!!;

function drawOne(i)
{
         //photos is a object that has been omitted for simplicity
    var picinfo = photos[Math.floor(Math.random()*photos.length)];
    checkduplicates.push(picinfo);

    img.onload = function()
    {
        var ctx = document.getElementsByClassName(\"canvas\")[i].getContext(\'2d\');
        // Draw pieces
        ctx.drawImage(img,0,0,132,150);
        //ctx.fillText(\"haha\",0,0);
        ctx.drawImage(frame,0,0,133,152);
        i++;
        if (i != canvaslength)
        {
             drawOne(i);
        }
    }
    //console.log(checkduplicates.length);
}
}