📅  最后修改于: 2022-03-11 14:52:53.332000             🧑  作者: Mango
var counter = 0;
function plus() {
counter += 1;
document.getElementById("counter").innerHTML = counter;
}
function minus() {
if(counter > 0){
counter -= 1;
}
document.getElementById("counter").innerHTML = counter;
}