// 一般写法
function fn(event) {
console.log(event)
}
div.onclick = function (event) {
fn(event)
}
====== 简化后=====
function fn(event) {
console.log(event)
}
div.onclick = fn
--------> 与下面相同
div.onclick(function(event){
console.log(event)
})
原文：https://www.cnblogs.com/PasserByOne/p/12075229.html