写例子说明js中自定义事件的使用与触发

var newEvent = new CustomEvent("build ", {  detail: {    dog: "wo",    cat: "mio"  },  bubbles: true,  cancelable: true,  composed: true});newEvent.name = "新的事件！";document.addEventListener("build ", function(e) {  console.log("你触发了自定义事件！" + newEvent.name)   console.log(" event.detail.dog:" + event.detail.dog + "n event.detail.cat:" + event.detail.cat)},false)document.dispatchEvent(newEvent);

CustomEvent-MDN