The read-only collapsed property of the AbstractRange interface returns true if the range's start position and end position are the same.
A collapsed range is empty (containing no content), and specifies a single point in a DOM tree. To collapse a range, see the Range.collapse() method.
A boolean value which is true if the range is collapsed. A collapsed range is one in which the start and end positions are the same, resulting in a zero-character-long range.
const range = document.createRange();
range.setStart(startNode, startOffset);
range.setEnd(endNode, endOffset);
const isCollapsed = range.collapsed;