Remove line breaks using apps scripts in a Google Document - google-apps-script

Question

Trying to work out how to remove multiple line breaks from Google Documents (not spreadsheets).
I've tried this and many variations thereof:
function searchAndReplace() {
var bodyElement = DocumentApp.getActiveDocument().getBody();
bodyElement.replaceText("\r\r", '\r');
}
Any idea please?
Noob to all of this...
Purpose is to replicate the search and replace in MS Word for ^p

Answer 1

Here is a rather "radical" method if your document has only paragraphs with text (images or other elements will be lost). See doc about element types here
(comments in code)
function removeNewLines(){
var doc = DocumentApp.getActiveDocument();
var text = doc.getBody().getText();// get a string
var textMod=text.replace(/\n/g,'');// replace all \n with ''
Logger.log(textMod);//optional check in logger
doc.getBody().clear().appendParagraph(textMod);// empty the doc and apend new texr
doc.saveAndClose();// save the result
}

Answer 2

I wanted to do the same thing (replace two new lines with a single new line). Ended up with the following as replaceText() doesn't accept \n for some reason.
function myFunction() {
var body = DocumentApp.getActiveDocument().getBody();
var text = body.editAsText();
var text_content = text.getText();
for(var i = 0, offset_i = 0; i < (text_content.length); i++){
if((text_content.charCodeAt(i)==10) && (text_content.charCodeAt(i-1)==10)){
text.deleteText(i-1-offset_i, i-1-offset_i)
offset_i++;
}
}
}

Answer 3

This code helped me to remove doubled new lines in document:
function removeDoubleNewLines(){
var doc = DocumentApp.getActiveDocument();
var paragraphs = doc.getBody().getParagraphs();
var paragraph;
for (var i = 0; i < paragraphs.length-1; i++) {
paragraph = paragraphs[i];
if(paragraph.getText() === '' &&
paragraph.getNumChildren() === 0) {
paragraph.removeFromParent();
}
}
}