如何以12小时格式(AM/PM)显示JavaScript datetime对象?
当前回答
这是最简单的方法,你可以实现这使用三元操作符,或者你也可以使用if else代替!
const d = new Date();
let hrs = d.getHours();
let m = d.getMinutes();
// Condition to add zero before minute
let min = m < 10 ? `0${m}` : m;
const currTime = hrs >= 12 ? `${hrs - 12}:${min} pm` : `${hrs}:${min} am`;
console.log(currTime);
其他回答
function formatTime( d = new Date(), ampm = true ) { var hour = d.getHours(); if ( ampm ) { var a = ( hour >= 12 ) ? 'PM' : 'AM'; hour = hour % 12; hour = hour ? hour : 12; // the hour '0' should be '12' } var hour = checkDigit(hour); var minute = checkDigit(d.getMinutes()); var second = checkDigit(d.getSeconds()); // https://stackoverflow.com/questions/1408289/how-can-i-do-string-interpolation-in-javascript return ( ampm ) ? `${hour}:${minute}:${second} ${a}` : `${hour}:${minute}:${second}`; } function checkDigit(t) { return ( t < 10 ) ? `0${t}` : t; } document.querySelector("#time1").innerHTML = formatTime(); document.querySelector("#time2").innerHTML = formatTime( new Date(), false ); <p>ampm true: <span id="time1"></span> (default)</p> <p>ampm false: <span id="time2"></span></p>
en-US的短RegExp:
var d = new Date();
d = d.toLocaleTimeString().replace(/:\d+ /, ' '); // current time, e.g. "1:54 PM"
查看Datejs。它们的内置格式化程序可以做到这一点:http://code.google.com/p/datejs/wiki/APIDocumentation#toString
这是一个非常方便的库,特别是如果您打算用date对象做其他事情时。
const formatAMPM = (date) => {
try {
let time = date.split(" ");
let hours = time[4].split(":")[0];
let minutes = time[4].split(":")[1];
hours = hours || 12;
const ampm = hours >= 12 ? " PM" : " AM";
minutes = minutes < 10 ? `${minutes}` : minutes;
hours %= 12;
const strTime = `${hours}:${minutes} ${ampm}`;
return strTime;
} catch (e) {
return "";
}
};
const startTime = "2021-12-07T17:00:00.073Z"
formatAMPM(new Date(startTime).toUTCString())
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>