How to encode text with JavaScript, how are parameters encoded when submitting html form?

Question

JavaScript

When sending a regular

html forms

<form accept-charset="UTF-8">
  <input name="text">
  <input type="submit">
</form>

a get parameter appears in the address bar:
?text=мой+текст+в+поле+ввода+%2B+%3D+.
How to encode text in input like this with js without submitting a form?
encodeURI(string), encodeURIComponent(string), escape(string)- these functions encode the text a little differently.
I apologize if I call things not by their proper names. Thanks in advance.