PHPの指定された日付範囲から日付を印刷できませんでした

Question

私は2つの日付値の間の日付範囲を印刷しようとしています。 ここまでは私が今まで何をしているのですか？

<?php  
     $getstartdate = getProjectstartdate($projectId); 
     $getenddate = getProjectenddate($projectId); 
     $begin = new DateTime($getstartdate); 
     $end = new DateTime($getenddate); 
     $daterange = new DatePeriod($begin, new DateInterval('P1D'), $end); 
     foreach($daterange as $date){ 
      echo $end; 
      echo $begin; 
      $dte = $date->format("Y-m-d"); 
      $day = date('D', strtotime($dte)); 
      echo '<a href="create-session-for.php?date='.$dte.'"><div class="'.$day.' date-box"><b>'.$day.'</b><br>'.$dte.'</div></a>'; 
     }  
    ?> 

のfunctions.php

function getProjectstartdate($project_id){ 
    $conn = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME); 
    if ($conn->connect_error) { 
     die("Connection failed: " . $conn->connect_error); 
    } 
    $sql = "SELECT project_start_date FROM projects WHERE id='$project_id'"; 
    $result = $conn->query($sql);  
    if ($result->num_rows > 0) { 
     while($row = $result->fetch_assoc()) {    
      $starts_by = $row["project_start_date"]; 
      return $starts_by; 
     } 
    } 
    $conn->close(); 
} 

function getProjectenddate($project_id){ 
    $conn = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME); 
    if ($conn->connect_error) { 
     die("Connection failed: " . $conn->connect_error); 
    } 
    $sql = "SELECT project_end_date FROM projects WHERE id='$project_id'"; 
    $result = $conn->query($sql);  
    if ($result->num_rows > 0) { 
     while($row = $result->fetch_assoc()) {    
      $ends_by = $row["project_end_date"]; 
      return $ends_by; 
     } 
    } 
    $conn->close(); 
} 

Answer 1

は、キャスト演算子(string)$yourObject;