How to check if some element has attribute “name” starts with something, not “value”

Question

I\'m going to use various data attributes names start with for example \"data-mo-\".

Assume I have these elements:

Answer 1

A concise approach using ES6 is to select all elements in the document, then .filter by whether .some of the attribute names start with the string you're looking for:

const moElements = [...document.querySelectorAll('*')]
  .filter(elm => [...elm.attributes].some(
    ({ name }) => name.startsWith('data-mo-')
  ));
console.log(moElements);

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Or, if you want to avoid constructing the intermediate arrays with spread, you can .call the array methods on the element / attribute collections instead:

const moElements = Array.prototype.filter.call(
  document.querySelectorAll('*'),
  elm => Array.prototype.some.call(
    elm.attributes,
    ({ name }) => name.startsWith('data-mo-')
  )
);
console.log(moElements);

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