domxpath/numbers.html

<!DOCTYPE html>
<link rel="help" href="https://www.w3.org/TR/1999/REC-xpath-19991116/#numbers">
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="helpers.js"></script>
<div id="context"></div>
<script>
test(() => {
  const context = document.querySelector('#context');
  context.innerHTML = '<span></span><span></span><span></span><br><br>';
  assert_equals(evaluateNumber('count((./span)[1]) + count(./br)', context), 3);
}, '"+" operator depending on the context node');

test(() => {
  const context = document.querySelector('#context');
  context.innerHTML = '<span></span><span></span><span></span><br><br>';
  assert_equals(evaluateNumber('count((./span)[1]) - count(./br)', context), -1);
}, '"-" operator depending on the context node');

test(() => {
  const context = document.querySelector('#context');
  context.innerHTML = '<span></span><span></span><span></span><br><br>';
  assert_equals(evaluateNumber('count((./span)[1]) * count(./br)', context), 2);
}, '"*" operator depending on the context node');

test(() => {
  const context = document.querySelector('#context');
  context.innerHTML = '<span></span><span></span><span></span><br><br>';
  assert_equals(evaluateNumber('count((./span)[1]) div count(./br)', context), 0.5);
}, '"div" operator depending on the context node');

test(() => {
  const context = document.querySelector('#context');
  context.innerHTML = '<span></span><span></span><span></span><br><br>';
  assert_equals(evaluateNumber('count((./span)[1]) mod count(./br)', context), 1);
}, '"mod" operator depending on the context node');
</script>
</body>