javascript - 我在做什么错（Javascript UpdateClock）

Question

我一直在尝试制作一个显示时间的简单 javascript 代码，但是当我设置数组并将其附加到 currentDay 时，它显示为“NaN”，你们能帮帮我吗？=]这是代码：

function updateTime(){
var currentTime = new Date();
var Wordday = new Array("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday");
var hours = currentTime.getHours()
if ( hours == 0 )  {
    hours = "0" ? 12 : hours
};
var minutes = currentTime.getMinutes();
if (minutes < 10){
    minutes = "0" + minutes;
};
var seconds = currentTime.getSeconds();
    if (seconds < 10){
    seconds = "0" + seconds;
};
var day = currentTime.getDay();
var t_str = + Wordday[day] + "&nbsp;" + hours + ":" + minutes + ":" + seconds + " ";
if(hours > 11){
    t_str += "AM";
} else {
    t_str += "PM";
};
document.getElementById('time_span').innerHTML = t_str;
}
setInterval(updateTime, 1000);

Answer 1

代替

var t_str = + Wordday[day] +....

和

var t_str =  Wordday[day] +...

现在它对我来说很好

Answer 2

一个问题是在

if (currentTime.getHours() < 12) {
    t_str += "AM";
} else {
    t_str += "PM";
};

演示：小提琴