SOURCE

function bind1() {
    console.log(1);
}
window.bind1 = bind1


$(function () {
    // 断点1
    document.querySelector('#btn1').onclick = function () {
        console.log(2);
    }

    document.querySelector('#btn1').addEventListener('click', function () {
        console.log(3);
    })

    $('#btn1').on('click', function () {
        console.log(4);
    })


    $(document).on('click', '#btn1', function () {
        console.log(5);
    })


})

<button id="btn1" onclick="bind1()">按钮1</button>