How can I emulate the jQuery $ selector in pure javascript? [closed]

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Using the jQuery $ selector makes getting DOM elements a lot easier. I want to be able to replicate this selector in plain javascript. How would I do this?

Note: I do not want to replace all instancew of $('')in my code with document.querySelector(), rather, I want to define $ as a function.

回答1:

You're looking for document.querySelectorAll(). You don't need to use the querySelectorAll method on document, it can be any DOM Element. If you want to use it in a style somewhat similar to jQuery, you can write a function that wraps it, like this:

var $ = function (selector) {
  return document.querySelectorAll(selector);
};

That example assumes you're using ES5 or older, and rewriting it in newer versions of the language should be trivial.

Keep in mind that this will return a NodeList, not an Array you might think it does, so many methods from it won't be there.

来源：https://stackoverflow.com/questions/51409162/how-can-i-emulate-the-jquery-selector-in-pure-javascript