Can one replace xhr.onreadystatechange with xhr.onload for AJAX calls?

Question

I need to support major modern browsers only (IE10+, FF, Chrome, Safari)

Can I make this substitution as I want to simplify my code base:

From:

Answer 1

You can clean up your first example by doing this

xhr.onreadystatechange = function () {
    if (this.readyState === 4 && this.status === 200) {
        o.callback(xhr.responseText);
    } else {
        return false;
    }
};

Note, you probably want to check onload too with this.status === 200 if you are doing something with the else statement. Although, if you are checking for errors, there is also onerror, which you can write something like

xhr.onerror = function(){
    console.log('Error: Do something else...');
}