//单独抽出的单例逻辑
var getSingle = function(fn){
var result = null; //创建一个变量来标记是否创建过对象,如果是则下次直接返回已创建过的对象
return function(){
if(!result){
result = fn.apply(this, arguments) //执行createLoginLayer函数结果返回div
}
return result
}
}
var createLoginLayer = function(){
div = document.createElement('div')
div.innerHTML = '我是登录弹窗'
div.style.display = 'none'
document.body.appendChild(div)
return div
}
var createSingleLoginLayer = getSingle(createLoginLayer)(1, 2, 3)