When it comes to writing out the code, is there a better time to use alert vs. console.log vs. document.write etc.?

alert: When you want to alert the user to something like 'unable to connect to database please try again later' console.log: for debugging messages or other error conditions you may not want the user to see document.write: when you are adding content to the page.

console.log.... if you're coding something for a user, you're not going to be using alert or document.write in most serious programs. You can use whatever you like if you're debugging, but logging things to the console is going to be the slickest way to go for most solutions. alert and document.write are often going to be used in tutorials as a quick and dirty way of displaying something in the interface itself.