Jquery get text value of some selector using index in array

Do like this, Use .each() function at this context to traverse over a collection of jquery object.

$(".timetable__table th").each(function(){
 console.log($(this).text());
});

.get(index) would return a javascript object and that does not contains a function called .text()

Note: Keep in mind that .size() has been deprecated from the version 1.8 use .length instead

because .get() returns the dom element not a jQuery object(the .text() is a method of jQuery wrapper object) use .eq() which will return a jQuery object

var ths = $(".timetable__table th");
var th;

for (var i = 0; i < ths.size(); i++) {
    th = ths.eq(i).text();
    console.log(th);
}

You need to iterate array like th[i] :

var ths = $(".timetable__table th");
var th;

    for (var i = 0; i < ths.size(); i++) {
      th  = ths[i].text();
      console.log(th);
    }  

But easiest way is below where you can skip for loop and simply use .each :

$(".timetable__table th").each(function(){
   console.log($(this).text());
});

.get() returns the underlying DOM element(s), which don't have a text() method. Use .eq() instead.

Looks like you didn't decide if you want to use the DOM or jQuery. Your code can be simplified to something like:

$(".timetable__table th").each(function(index, el) {
    console.log($(el).text());
});