now.js

/**
 * 获取当前时间
 *
 * @return {string}
 */
function now() {
    const now = new Date();
    return "[" + stringAlignRight(now.getFullYear(), 4, "0") + "-" + stringAlignRight(now.getMonth() + 1, 2, "0") + "-" + stringAlignRight(now.getDate(), 2, "0") +
        " " + stringAlignRight(now.getHours(), 2, "0") + ":" + stringAlignRight(now.getMinutes(), 2, "0") + ":" + stringAlignRight(now.getSeconds(), 2, "0") + "." + stringAlignRight(now.getMilliseconds(), 3, "0") + "]";
}

/**
 * 把字符串右对齐到指定的长度，长度不足时使用给定的字符填充左边
 *
 * @param s { any } 要对齐的字符串
 * @param length { number} 要对齐到的长度
 * @param c { string } 长度不足时用什么字符补齐
 * @return { string }
 */
function stringAlignRight(s, length, c) {
    s = s + "";
    while (s.length < length) {
        s = c + s;
    }
    return s;
}

// 直接调用方法会返回格式化好的当前时间
console.log(now());
// Output: [2023-12-27 22:45:15.082]