如何以12小时格式(AM/PM)显示JavaScript datetime对象?


当前回答

下面是一种使用regex的方法:

console.log(新日期(“7/10/2013 20:12:34”).toLocaleTimeString () .replace (/ ((\ d) +: \ d {2}) (: \ [d] {2 })(.*)/, "$ 1美元3”)) console.log(新日期(“7/10/2013 01:12:34”).toLocaleTimeString () .replace (/ ((\ d) +: \ d {2}) (: \ [d] {2 })(.*)/, "$ 1美元3”))

这将创建3个匹配组:

([\d]+:[\d]{2}) -小时:分钟 (:[\d]{2}) -秒 (.*) -空格和时段(时段是AM/PM的正式名称)

然后显示第1组和第3组。

警告:toLocaleTimeString()可能会根据区域/位置表现不同。

其他回答

如果你不需要打印上午/下午,我发现以下内容很好很简洁:

var now = new Date();
var hours = now.getHours() % 12 || 12;  // 12h instead of 24h, with 12 instead of 0. 

这是基于@bbrame的回答。

查看Datejs。它们的内置格式化程序可以做到这一点:http://code.google.com/p/datejs/wiki/APIDocumentation#toString

这是一个非常方便的库,特别是如果您打算用date对象做其他事情时。

更新以获得更多压缩

const formatAMPM = (date) => {
  let hours = date.getHours();
  let minutes = date.getMinutes();    
  const ampm = hours >= 12 ? 'pm' : 'am';

  hours %= 12;
  hours = hours || 12;    
  minutes = minutes < 10 ? `0${minutes}` : minutes;

  const strTime = `${hours}:${minutes} ${ampm}`;

  return strTime;
};

console.log(formatAMPM(new Date()));

下面是一种使用regex的方法:

console.log(新日期(“7/10/2013 20:12:34”).toLocaleTimeString () .replace (/ ((\ d) +: \ d {2}) (: \ [d] {2 })(.*)/, "$ 1美元3”)) console.log(新日期(“7/10/2013 01:12:34”).toLocaleTimeString () .replace (/ ((\ d) +: \ d {2}) (: \ [d] {2 })(.*)/, "$ 1美元3”))

这将创建3个匹配组:

([\d]+:[\d]{2}) -小时:分钟 (:[\d]{2}) -秒 (.*) -空格和时段(时段是AM/PM的正式名称)

然后显示第1组和第3组。

警告:toLocaleTimeString()可能会根据区域/位置表现不同。

或者只是简单地执行以下代码:

    <script>
        time = function() {
            var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
            m = checkTime(m);
            s = checkTime(s);
            document.getElementById('txt_clock').innerHTML = h + ":" + m + ":" + s;     
            var t = setTimeout(function(){time()}, 0);
        }

        time2 = function() {
            var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
            m = checkTime(m);
            s = checkTime(s);
            if (h>12) {
                document.getElementById('txt_clock_stan').innerHTML = h-12 + ":" + m + ":" + s;
            }               
            var t = setTimeout(function(){time2()}, 0);
        }

        time3 = function() {
            var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
            if (h>12) {
                document.getElementById('hour_line').style.width = h-12 + 'em'; 
            }
            document.getElementById('minute_line').style.width = m + 'em';  
            document.getElementById('second_line').style.width = s + 'em';  
            var t = setTimeout(function(){time3()}, 0);
        }

        checkTime = function(i) {
            if (i<10) {i = "0" + i};  // add zero in front of numbers < 10
            return i;
        }           
    </script>