How to run javascript code without thread?

I'm Beginner in Javascript. I learned python before. In javascript, I noticed that javascript runs every function with thread. Example:

$.ajax({
        url:'/',
        type:'GET',
        success:function(){
            console.log('Response Found!')
        },
        error:function(){
            console.log('Error connecting to the site.')
        },
    })

console.log('All done!')

Here a jquery ajax request and a console log function. I want to execute ajax request before console log. But the result is:

Console log execute before ajax request. Can any one tell how to wait till the ajax function is completed?