Question

我正在尝试将带有array_push的随机数添加到'notes'=> []字段中的数组，但我认为这样做不正确，因为我看不到数组中存储的随机数。 / p>

我通过以下方式进行操作：

$person1= [
    'name' => 'person1',
    'note' => []
];

$person2= [
    'name' => 'person2',
    'note' => []
];

$person3= [
    'name' => 'person3',
    'note' => []
];

$data=[$person1, $person2, $person3];
$_SESSION['data'] = $data;


function insertNumRandom(){

   $data = $_SESSION['data'];

   foreach ( $data as $student ) {

      array_push($student['note'], rand(0,10));
    }
}

function showNotes(){

    foreach ( $data as $student ) {

        echo implode($student['note']);
    }
}

showNotes(); // To show the notes but it shows nothing.

Answer 1

您应按如下所示更改insertNumRandom

function insertNumRandom(){
    $data = $_SESSION['data'];
    foreach ( $data as &$student ) {
        array_push($student['note'], rand(0,10));
    }
    $_SESSION['data'] = $data;
}

showNotes函数

function showNotes(){
    $data = $_SESSION['data'];
    foreach ( $data as $student ) {
        echo implode($student['note']);
    }
}

并在showNotes之前调用insertNumRandom。

insertNumRandom();
showNotes();

Answer 2

您正在使用$ as关键字引用$ data来创建一个新对象。

您应该改为遍历现有对象。

var MyObj = function(x) {
   this.x = x;
   this.y = 5;
};

MyObj.prototype.example = function() {
   // I want to return a new object which has access to this.x and this.y

   var addTwo = function() {
     return 2 + this.x
   }
   // For example:
   return {
      addTwo: addTwo.bind(this)
   }
};

Answer 3

也许可以尝试一下，仍然不确定如何调用insertNumRandom()函数

function showNotes($arr){

    foreach ( $arr as $student ) {

       var_dump(implode($student['note']));
    }
}

insertNumRandom();

showNotes($data);

Answer 4

您的示例中有很多问题。

首先，使用$ _SESSION对象将一些值传递给函数的方式不是必需的，而且也不是很干净。您可以在函数内部使用global $data，它们会突然从父作用域访问$ data变量。但这还不是很干净。我建议您通过引用函数传递数据对象。这将使您的功能更加可移植和可测试。
您的示例正在按值访问$ student变量。您所需要做的就是通过使用像foreach ( $data as &$student ) { ... }
我注意到您从未致电insertNumRandom()
为了更好地了解数组中的内容，建议您为implode（）函数使用字段分隔符，并在对数组进行内插后打印新行。我敢打赌，您会喜欢结果的。
最后，仅需提一个建议... array_push（）可让您将一个或多个项目推入数组。但是我只在需要将多个项目推入数组时才使用它。对于仅推送新项目，我使用简写$myArray[] = "new item";

所以在实践中，这就是您的示例...

<?php
// Since you are not reusing $person1, $person2 and $person3 beyond the initialization
// phase, then let's keep things cleaner.
$data[] = [
  'name' => 'person1',
  'note' => []
];
$data[] = [
  'name' => 'person2',
  'note' => []
];
$data[] = [
  'name' => 'person3',
  'note' => []
];

/**
 * In this function signature, the & means that the argument is passed by reference.
 * That make it possible for the function to change the value of the argument.
 */
function insertNumRandom(&$theData) {
  // The foreach() also needs to use $student by reference so that we can modify it
  // by adding the random number to it.
  foreach($theData as &$student) {
    $student['note'][] = rand(0,10);
  }
}

/**
 * No need to pass $theData by reference because the function will not change its value.
 */
function showNotes($theData) {
  // Here, the foreach() is using student by value because we do not need to change it's value.
  foreach($theData as $student) {
    echo implode($student['note'], ', ') . "\n";
  }
}

// Inserting some random notes 3 times.
insertNumRandom($data);
insertNumRandom($data);
insertNumRandom($data);
showNotes($data); // To show the notes but it shows nothing.

?>

向数组添加值

4 个答案: