如何获取AM或PM？

function getAmPm(timeString) {
    return timeString.slice(-2);
}

console.log(getAmPm("10:00 AM")); // 输出 "AM"
console.log(getAmPm("4:00 PM"));  // 输出 "PM"

function getAmPmFromDate(date) {
    let hours = date.getHours();
    let ampm = hours >= 12 ? 'PM' : 'AM';
    return ampm;
}

let now = new Date();
console.log(getAmPmFromDate(now)); // 输出当前时间的AM或PM

function isValidTimeString(timeString) {
    let regex = /^(0?[1-9]|1[0-2]):[0-5][0-9] (AM|PM)$/;
    return regex.test(timeString);
}

if (isValidTimeString("10:00 AM")) {
    console.log(getAmPm("10:00 AM")); // 输出 "AM"
} else {
    console.log("Invalid time string");
}

let date = new Date();
date.toLocaleTimeString('en-US', { hour12: true }); // 使用本地时区并显示12小时制时间