JavaScript why even in that structure need quotations

 console.log(tagline.indexOf('x'));

And that already is in parenthesys why need quotation? Thinking about and seeing the reason does help to remember because you learned because the -->x could be a variable I could have almost the infinity of possibilities for names of variables and is valid in the place of write x what I want to store the x in a variable and call the x by the name of the variable, so the machine needs to know that what you are looking for if is the x naming 'x' or for one variable with the name x and this one doesn't have quotations. Rute Bezerra de Menezes Gondim