Laravel: Optional variable in blade template? - php

Question

I have a quiz app and when I press add question button the error Undefined variable: question $question is undefined. Make the variable optional in the blade template. Replace {{ $question }} with {{ $question ?? '' }} occurs. The error appear for line 13 and 17:
<div class="form-group">
{!! Form::label('title', 'Title'); !!}
{{ Form::text('title', null, ['class' => 'form-control input-editor', 'placeholder' => 'Title']) }}
</div>
<div class="form-group">
{!! Form::label('category_id', 'Category'); !!}
<select class="form-control" id="category_id" name="category_id">
<option selected="selected" value="">---Pick a Category---</option>
#foreach($categories as $key => $cat)
#if(!empty($child_categories[$key]))
<optgroup label="{{ $cat }}">
#foreach($child_categories[$key] as $ckey => $ccat)
<option value="{{ $ckey }}" {{ $question->category_id == $ckey ? 'selected' : '' }}>{{ $ccat }}</option>
#endforeach
</optgroup>
#else
<option value="{{ $key }}" {{ $question->category_id == $key ? 'selected' : '' }}>{{ $cat }}</option>
#endif
#endforeach
</select>
</div>
<div class="form-group">
{!! Form::label('question_type', 'Question Type'); !!}
{!! Form::select('question_type', ['regular' => 'Regular Question', 'photo' => 'Photo Question'], null, ['id' => 'question_type', 'class' => 'form-control']); !!}
</div>
#if($btntitle == 'Update Question')
<div class="alert alert-success question_image" style="{{ isset($question) && $question->question_type == 'photo' ? 'display: block;' : 'display: none;' }}">
Upload image if you want to ovewrite existing one(if any), otherwise leave that field blank
</div>
#endif