相当于在 jQuery 中将侦听器附加到文档就绪按钮，而不是香草 JavaScript？

Question

How do I convert this JavaScript code to jQuery code?

if (document.readyState == 'loading') {
    document.addEventListener('DOMContentLoaded', ready)
} else {
    ready()
}

function ready() {
    var removeCartItemButtons = document.getElementsByClassName('btn-danger')
    for (var i = 0; i < removeCartItemButtons.length; i++) {
        var button = removeCartItemButtons[i]
        button.addEventListener('click', removeCartItem)
    }
}

Answer 1

Running something when the document is ready is handled by the $( document ).ready() method.

getElementByClassName can be replaced by a Class Selector (".class")

Your for loop can be removed because with jQuery methods all are called on each returned element.

addEventListener can be replaced by .click() .

Then your code is just three lines long:

$(function(){
    $('.btn-danger').click(removeCartItem)
})

Answer 2

jQuery is a library of Javascript, and therefore nothing needs to be converted.