I'm new and I'm testing the blob function I want to know how do I view the output for this function of convertImgToBase64URL I want to know the different between the method 1 and method 2.

Method 1

function convertImgToBase64URL(url, callback, outputFormat){
    var img = new Image();
    img.crossOrigin = 'Anonymous';
    img.onload = function(){
        var canvas = document.createElement('CANVAS'),
        ctx = canvas.getContext('2d'), dataURL;
        canvas.height = img.height;
        canvas.width = img.width;
        ctx.drawImage(img, 0, 0);
        dataURL = canvas.toDataURL(outputFormat);
        callback(dataURL);
        canvas = null; 
    };
    img.src = url;
    }
    convertImgToBase64URL('http://upload.wikimedia.org/wikipedia/commons/4/4a/Logo_2013_Google.png', function(base64Img){
    alert('it works');
        $('.output').find('img').attr('src', base64Img);  
    });
   

Method 2

 fetch('https://upload.wikimedia.org/wikipedia/commons/7/77/Delete_key1.jpg')
        .then(res => res.blob())
        .then(blob => {
            
            myBlob = blob;
            console.log(myBlob);
        });

For the Method 2, I can see how it turn output into. But I'm not quite sure about the Method 1. What should I console.log in Method 1 if I want to see the output like Method 2 ?