使用strlen（）函数检查字符串是否有11个字符

Question

我已经实现了一个用户注册表单，并且我需要检查ABN字段是否正好有11个字符。我为此写了一个if else语句。但据说即使有人输入了11个字符，也会弹出错误信息。 if-else语句可能有问题。虽然我是编程新手，但很难发现错误。我已经更改了if-else的展示位置，但我无法修复它。任何形式的帮助将非常感激。我会把我的编码放在下面。谢谢！

if($_POST){ 
    //validate email 
    if(empty($_POST['email']) || empty($_POST['password']) || empty($_POST['confirm']) || empty($_POST['firstname']) || empty($_POST['lastname']) ||empty($_POST['companyname']) || empty($_POST['companyphone'])||empty($_POST['abn'])||empty($_POST['type'])||empty($_POST['position'])||empty($_POST['phone']) || empty($_POST['address1']) || empty($_POST['city']) || empty($_POST['state']) || empty($_POST['country']) || empty($_POST['postcode'])){ 
    $errors[] = 'You must fill out required field.'; 
    } else { 
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)){ 
     $errors[] = 'You must enter a valid email.'; 
    }else { 
     $query = "SELECT * FROM users WHERE email=?"; 
     $stmt = $db->prepare($query); 
     $stmt->bind_param("s", $email); 
     $stmt->execute(); 
     $result = $stmt->get_result(); 
     $user = mysqli_fetch_assoc($result); 
     $stmt->execute(); 
     $stmt->store_result(); 
     $userCount = $stmt->num_rows(); 
     // Check if the email already exists in database. 
     if($userCount > 0){ 
     $errors[] = 'That email already exists.'; 
     } else { 
     //check if password is not less than 6 characters 
     if (strlen($password) < 6) { 
      $errors[] = 'Password must be at least 6 characters.'; 
     }else { 
      // check if passwords match 
      if($password !=$confirm){ 
      $errors[] = 'The passwords do not match.'; 
      } 
      else{ 
      if(strlen($abn)< 11) 
      {$errors[] = 'ABN Should be 11 characters.';} 
      } 

     } 
     } 
    } 
    } 

Answer 1

正如你说，你strlength应该正好11所以你的if语句应该是这样的

if(strlen($abn)!=11) { $errors[] ='ABN Should be 11 characters.'; }