php 检查 url 中是否存在变量并替换值

Question

我写了一个函数，允许我进行分页。问题来了：当我单击按钮将页面更改为 URL 时，会添加许多相同的值，如下所示：

时事通讯.php？action=sent-emails&page=2&page=1&page=4&page=5&page=7&page=5&page=1

function pagination($sql_general,$page_name_pagination,$page_query_pagination) {

  require $_SERVER['DOCUMENT_ROOT'] . 'it/intranet/includes/dbh.inc.php';

  $sql1 =  $sql_general;

  $sql1_query = mysqli_query($conn, $sql1);

  $total = mysqli_num_rows($sql1_query);

  $adjacents = 3;

  $targetpage = $page_name_pagination; //your file name

  if (!empty($page_query_pagination)) {

    $targetpage .= "?" . $page_query_pagination . "&page=";

  } else {

    $targetpage .= "?page=";

  }

  $limit = 10; //how many items to show per page

  $page = $_GET['page'];

  if($page){

  $start = ($page - 1) * $limit; //first item to display on this page

  }else{

  $start = 0;

  }

  /* Setup page vars for display. */

  if ($page == 0) $page = 1; //if no page var is given, default to 1.

  $prev = $page - 1; //previous page is current page - 1

  $next = $page + 1; //next page is current page + 1

  $lastpage = ceil($total/$limit); //lastpage.

  $lpm1 = $lastpage - 1; //last page minus 1

  $pagination = "";

  if($lastpage > 1)

  {

  $pagination .= "<div class='pagination1'> <ul class='pagination'>";

  if ($page > $counter+1) {

  $pagination.= "<li class='page-item'><a class='page-link' href=\"$targetpage$prev\"><</a></li>";

  }

  if ($lastpage < 7 + ($adjacents * 2))

  {

  for ($counter = 1; $counter <= $lastpage; $counter++)

  {

  if ($counter == $page)

  $pagination.= "<li class='page-item'><a class='page-link' href='#' >$counter</a></li>";

  else

  $pagination.= "<li class='page-item'><a class='page-link' href=\"$targetpage$counter\">$counter</a></li>";

  }

  }

  elseif($lastpage > 5 + ($adjacents * 2)) //enough pages to hide some

  {

现在，如何检查“page=x”是否存在并替换该值？

Answer 1

拆分、修改/添加和撰写：parse_str($query_string,$list);if (isset($list['name']){&nbsp; &nbsp; &nbsp;// name= exists, modify it}else{&nbsp; &nbsp; &nbsp;// name= not exists&nbsp; &nbsp; &nbsp;$list['name'] = "new value";}$query_string = http_build_query($list);