此问题已在此处有答案：

Reference Guide: What does this symbol mean in PHP? (PHP Syntax)（25个回答）
8天前关闭
我试图让我的头周围这下面的代码，相对较新的php/mysql它有点挠头，我试图解决的部分是进度/百分比的一部分。

$prog = $tprog > 0 ? ($cprog/$tprog) * 100 : 0;

$prog = $prog > 0 ?  number_format($prog,2) : $prog;

如果有人能解释就好了

<?php
            $i = 1;
            $stat = array("Started (Received by Client)","In-Progress (with Estimator)","Complete (Handed to Delivery)");
            $where = "";
            if($_SESSION['login_type'] == 2){
              $where = " where manager_id = '{$_SESSION['login_id']}' ";
            }elseif($_SESSION['login_type'] == 3){
              $where = " where concat('[',REPLACE(user_ids,',','],['),']') LIKE '%[{$_SESSION['login_id']}]%' ";
            }
            $qry = $conn->query("SELECT * FROM project_list $where order by name asc");
            while($row= $qry->fetch_assoc()):
              $prog= 0;
            
            $tprog = $conn->query("SELECT * FROM task_list where project_id = {$row['id']}")->num_rows;
            $cprog = $conn->query("SELECT * FROM task_list where project_id = {$row['id']} and status = 3")->num_rows;
            $prog = $tprog > 0 ? ($cprog/$tprog) * 100 : 0;
            $prog = $prog > 0 ?  number_format($prog,2) : $prog;
            $prod = $conn->query("SELECT * FROM user_productivity where project_id = {$row['id']}")->num_rows;
            if($row['status'] == 0 && strtotime(date('Y-m-d')) >= strtotime($row['start_date'])):
            if($prod  > 0  || $cprog > 0)
              $row['status'] = 2;
            else
              $row['status'] = 1;
            elseif($row['status'] == 0 && strtotime(date('Y-m-d')) > strtotime($row['end_date'])):
            $row['status'] = 4;
            endif;
              ?>