📅  最后修改于: 2022-03-11 15:03:58             🧑  作者: Mango
function executeIfFileExist(src, callback) {
var xhr = new XMLHttpRequest()
xhr.onreadystatechange = function() {
if (this.readyState === this.DONE) {
callback()
}
}
xhr.open('HEAD', src)
}