Class Range

A range of elements in a document. The user's selection is represented as a Range, among other uses. Scripts can only access the selection of the user who is running the script, and only if the script is bound to the document.

 

 // Bold all selected text.
 var selection = DocumentApp.getActiveDocument().getSelection();
 if (selection) {
   var elements = selection.getRangeElements();
   for (var i = 0; i < elements.length; i++) {
     var element = elements[i];

     // Only modify elements that can be edited as text; skip images and other non-text elements.
     if (element.getElement().editAsText) {
       var text = element.getElement().editAsText();

       // Bold the selected part of the element, or the full element if it's completely selected.
       if (element.isPartial()) {
         text.setBold(element.getStartOffset(), element.getEndOffsetInclusive(), true);
       } else {
         text.setBold(true);
       }
     }
   }
 }