TiaoZhan_Homework/4/index.ts

26 lines
862 B
TypeScript

let t = 0;
let b1 = <HTMLElement>document.getElementsByClassName("b1")[0],
b2 = <HTMLElement>document.getElementsByClassName("b2")[0],
b3 = <HTMLElement>document.getElementsByClassName("b3")[0],
timer = <HTMLElement>document.getElementsByClassName("timer")[0];
function c_timer() {
console.log(t);
t += 1;
if (t == 13) t = 0;
if (t < 6) {
b3.style["background-color"] = "unset";
b1.style["background-color"] = "red";
timer.innerHTML = 6-t as string;
}
else if(t<8){
b1.style["background-color"] = "unset";
b2.style["background-color"] = "green";
timer.innerHTML = 8-t as string;
}
else if(t<13){
b2.style["background-color"] = "unset";
b3.style["background-color"] = "yellow";
timer.innerHTML = 13-t as string;
}
}
setInterval(c_timer, 1000);