Question

我是Laravel的绝对初学者，甚至是php。

我想删除下面的数组元素。

英语不是我的第一语言，所以如果这个问题对您没有意义，请留下您的意见。任何意见，将不胜感激！提前谢谢！

myController的

public function deleteLog(Course $course, CreateCourseRequest $request){

    $courseWeeks = $course->weeks;
    $courseWeeksCount = intval($courseWeeks);

    $inputWeeks = $request->input('weeks');
    $inputWeeksCount = intval($inputWeeks);

    $inputUsers = $request->input('first_name_list');

    for ($i = $courseWeeksCount; $i >= $inputWeeksCount; $i--) {
        foreach($inputUsers as $user) {
             /* I need to write code that deletes certain numbers of elements of array. 
                For example, when the admin changes the weeks of the course 'intro to php' 
                from 5 to 3, logs whose number of weeks are 4 and 5 will be deleted   */
        }
    }
}

基本上，我想与下面的addLog函数相反。

 public function addLog(Course $course, CreateCourseRequest $request){

    $courseWeeks = $course->weeks;
    $courseWeeksCount = intval($courseWeeks);

    $inputWeeks = $request->input('weeks');
    $inputWeeksCount = intval($inputWeeks);

    $inputUsers = $request->input('first_name_list');

    $logs = array();

    for ($i = $courseWeeksCount; $i <= $inputWeeksCount; $i++) {
        foreach($inputUsers as $id) {
            array_push($logs, array(
                'user_id' => $id,
                'course_id' => $course->id,
                'weeks' => $i,
                'work_description' => '',
                'instructor_comments' => '',
                'status' => 'accepted',
                'created_at' => Carbon::now(),
                'updated_at' => Carbon::now(),
            ));
        }
    }
    Log::insert($logs);
}

在MyController中，有以下功能。

if($this->AreInputWeeksLess($course, $request)){
        //$this->deleteLog($course, $request);
}

public function AreInputWeeksLess(Course $course, CreateCourseRequest $request){
    $courseWeeks = $course->weeks;
    $courseWeeksCount = intval($courseWeeks);

    $inputWeeks = $request->input('weeks');
    $inputWeeksCount = intval($inputWeeks);

    if($inputWeeksCount - $courseWeeksCount < 0){
        return true;
    } else{
        return false;
    }
}

Course_Edit.blade.php

<div class = "form-group">
    {!! Form::label('weeks', 'Weeks:') !!}
    {!! Form::selectRange('weeks', 1, 17) !!}
</div>

<div class = "form-group">
    {!! Form::label('first_name_list', 'Students:') !!}
    {!! Form::select('first_name_list[]', $students, null, ['id' => 'first_name_list' ,'class' => 'form-control', 'multiple']) !!}
</div>

Answer 1

在许多选项中，我建议使用两种非常基本的解决方案，这些解决方案不是很干净，但很简单且很少：

将此数组转换为集合并使用集合方法来搜索和删除项目。

例如：

$fruitArray = [
    ['fruit'   => 'apple',
     'fruitId' => 'appleId',
     'price'   => 10
    ],
    ['fruit'   => 'banana',
     'fruitId' => 'bananaId',
     'price'   => 10
    ],
    ['fruit'   => 'mango',
     'fruitId' => 'mangoId',
     'price'   => 10
    ]
]; // this is your array structure

$collection = \Illuminate\Support\Collection::make($fruitArray);

$filteredCollection = $collection->reject(function ($item) {
    if (array_get($item, 'fruit') === 'mangoId') {
        return false;
    } else {
        return true;
    }
}); // using callback function call we saying reject item from collection. Function callback decides what stays what not. If call back returns false item is removed from collection.

// Next step is unecessary but if you comfortable with arrays only convert your collection back to array.
$fruitArray = $collection->toArray();

使用数组中的查找：

$logs[] =
    [
        'user_id'             => 1,
        'course_id'           => 1,
        'weeks'               => 1,
        'work_description'    => '',
        'instructor_comments' => '',
        'status'              => 'accepted',
        'created_at'          => Carbon::now(),
        'updated_at'          => Carbon::now(),
    ];


// you don't even need those two horrible for loops instead do something like below

$logs = array_map(function ($item) use ($courseWeekCount, $inputCourseWeek) {
    if ($inputCourseWeek < $courseWeekCount) {
        if (array_get('$item', 'week') <= $inputCourseWeek) {
            return $item;
        } else {
            return [];
        }
    } else {
        return $item;
    }
}, $logs);

Laravel：5.0如何删除数组

1 个答案: