Laravel 5.2 Data Update Not Working : Showing Error

I am using Laravel 5.2 PHP framework.When i try to update any data it's through an Error.I don't why is this happening? I have searched in google but i can not get any result which is solve my problem.

My routes.php:

Route::group(['prefix' => 'jobs'], function () {
    Route::get('all', ['as' => 'allJobs' , 'uses' => 'JobController@index']);
    Route::get('create', ['as' => 'addNewJobs' , 'uses' => 'JobController@create']);
    Route::post('save', ['as' => 'saveJob' , 'uses' => 'JobController@store']);
    Route::get('edit/{id}', ['as' => 'editJobs' , 'uses' => 'JobController@edit']);
    Route::put('update', ['as' => 'updateJob' , 'uses' => 'JobController@update']);
    Route::get('delete/{id}', ['as' => 'deleteJob' , 'uses' => 'JobController@destroy']);

});

My JobController.php:

public function update(Request $request, $id=0)
{
    $id = $request->input("id");        
    $job = Jobs::find($id);
    $job->jobTitle = $request->input('jobTitle');
    $job->jobCat = $request->input('jobCat');
    $job->jobSummary = $request->input('jobSummary');

    $job->save();        
    return redirect(route('allJobs'));
}

Error:

I really don't know where is the problem? Could any one tell me the solution of it?

NOTE: I can give you more information if you need.

via Chebli Mohamed