Question

first_tuesday()函数应返回一年中第一个星期二的日期，但特别是在2011年的情况下，它会返回错误的值。如何修复代码，使其适用于所有情况

function first_tuesday($year){

    $first_january = mktime(0,0,0,1,1,$year);
    $day_week = date("w",$first_january );
    $first_tuesday = $first_jan + ((2 - $day_week) % 7)* 86400;
    return date("d/m/Y",$first_tuesday);
}

Answer 1

strtotime足够聪明，可以得到你想要的东西：

function first_tuesday($year){
  return date('d/m/Y', strtotime("first Tuesday of January $year"));
}

Answer 2

改为使用DateTime类：

function first_tuesday($year){
    $day = new DateTime(sprintf("First Tuesday of January %s", $year));
    return $day->format('d/m/Y');
}

用法：

echo first_tuesday(2011);

输出：

04/01/2011

Answer 3

这似乎对我有用：

<?php

$first_tuesday = new DateTime("first Tuesday of January 2011");
echo $first_tuesday->format('Y-m-d H:i:s');

?>

将其置于功能形式：

<?php

/**
 * @return DateTime Returns a DateTime object representing the
 *                  first Tuesday of the year
 */
function first_tuesday($year){
    $first_tuesday = new DateTime("first Tuesday of January $year");
    return $first_tuesday;
}

?>

如果您只想要格式的字符串，那么：

<?php

/**
 * @return DateTime Returns a string representing the first
 *                  Tuesday of the year in the d/m/Y format
 */
function first_tuesday($year){
    $first_tuesday = new DateTime("first Tuesday of January $year");
    return $first_tuesday->format('d/m/Y');
}

?>

您可以在PHP手册中阅读有关DateTime课程的更多信息（也可以使用法语版本，因为根据原始问题，这似乎是您的母语。）

Answer 4

$start_of_year = strtotime("01.01.2011");
$first_tuesday = strtotime("tuesday", $start_of_year);

echo date('d.m.Y', $first_tuesday); // 04.01.2011

Answer 5

简单：

function first_tuesday($year)
{
    return date("d/m/Y",strtotime('first Tuesday january '.$year));
}

无需使用对象，这是获取对象的最快方法。

第一个星期二PHP

5 个答案: