Range: comparePoint() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2017.

The comparePoint() method of the Range interface determines whether a specified point is before, within, or after the Range. The point is specified by a reference node and an offset within that node.

Syntax

comparePoint(referenceNode, offset)

Parameters

referenceNode: The Node that the offset is relative to.
offset: An integer greater than or equal to zero describing the position inside referenceNode of the point to be checked. If referenceNode is a Node of type Text, Comment, or CDATASection, then offset is the number of characters from the start of referenceNode. For other Node types, offset is the number of child nodes from the start of the referenceNode.

Return value

A number.

-1 if the point specified by the referenceNode and offset is before the start of this Range.
0 if the point specified by the referenceNode and offset is within this Range (including the start and end points of the range).
1 if the point specified by the referenceNode and offset is after the end of this Range.

Examples

const text = new Text("0123456789");

const thisRange = new Range();
thisRange.setStart(text, 1);
thisRange.setEnd(text, 6);

thisRange.comparePoint(text, 3); // 0
thisRange.comparePoint(text, 0); // -1
thisRange.comparePoint(text, 6); // 0
thisRange.comparePoint(text, 7); // 1

Specifications

Specification
DOM # ref-for-dom-range-comparepoint①