如何在php中使用函数添加关联数组？

Question

所以我需要一个函数能够将元素添加到关联数组，以及计数器来计算此函数调用的数量。 这是我走到这一步：

<?php 
    //1 
    $Globals = []; 
    $counter = 0; 
    function array_push_assoc($course, $courseCode, $courseName){ 
    $course[courseCode] = $courseName; 
    return $course(); 
    $counter ++; 
} 
    $Globals = array_push_assoc($Globals, 'CIS370', 'Introduction to Web Development'); 
    $Globals = array_push_assoc($Globals, 'CIS475', 'Advance Web Development'); 
    $Globals = array_push_assoc($Globals, 'CIS560', 'Introduction to Syber Security'); 
    $Globals = array_push_assoc($Globals, 'CIS564', 'Hacking Technic'); 
    //2 
    echo 'You have a total of $counter courses now!'; 
?> 

显然，这是错误的，有人可以让我知道在哪里以及如何做到这一点正常吗？ 谢谢

Answer 1

你的代码有很多问题。

• 您返回一个函数与数组？我没有看到你要在这里做什么，只需返回数组。

return $course();

到

return $course;

• 你回来之前，你实际上会增加计数器变量，所以它从来没有得到递增！

所以：

$course[courseCode] = $courseName; 
return $course; 
$counter ++; 

到

$course[courseCode] = $courseName; 
$counter++; 
return $course; 

• 你不能传递一个计数器变量的任何地方。要做你想做的事，你需要通过引用将它传递给函数。

所以：

function array_push_assoc($course, $courseCode, $courseName) 
{ 
    $course[$courseCode] = $courseName; 
    $counter++; 
    return $course; 
} 

到

function array_push_assoc($course, $courseCode, $courseName, &$counter) 
{ 
    $course[$courseCode] = $courseName; 
    $counter++; 
    return $course; 
} 

这里是固定的最终代码：

<?php 
//1 
$Globals = []; 
$counter = 0; 
function array_push_assoc($course, $courseCode, $courseName, &$counter) 
{ 
    $course[$courseCode] = $courseName; 
    $counter++; 
    return $course; 
} 

$Globals = array_push_assoc($Globals, 'CIS370', 'Introduction to Web Development', $counter); 
$Globals = array_push_assoc($Globals, 'CIS475', 'Advance Web Development', $counter); 
$Globals = array_push_assoc($Globals, 'CIS560', 'Introduction to Syber Security', $counter); 
$Globals = array_push_assoc($Globals, 'CIS564', 'Hacking Technic', $counter); 
//2 
echo 'You have a total of $counter courses now!'; 

Answer 2

这是做这个的非常奇怪的方式。如果你绝对必须这样做，在你的代码暗指的方式，这将工作：

$Globals = []; 
$counter = 0; 

function array_push_assoc($course, $courseCode, $courseName, &$count){ 
    $course[$courseCode] = $courseName; 
    $count++; 
    return $course; 
} 

$Globals = array_push_assoc($Globals, 'CIS370', 'Introduction to Web Development', $counter); 
$Globals = array_push_assoc($Globals, 'CIS475', 'Advance Web Development', $counter); 
$Globals = array_push_assoc($Globals, 'CIS560', 'Introduction to Syber Security', $counter); 
$Globals = array_push_assoc($Globals, 'CIS564', 'Hacking Technic', $counter); 

echo "You have a total of {$counter} courses now!"; 

那说，这样做的更清洁（IMO）的方法是：

$Globals = []; 
$Globals['CIS370'] = 'Introduction to Web Development'; 
$Globals['CIS475'] = 'Advance Web Development'; 
$Globals['CIS560'] = 'Introduction to Syber Security'; 
$Globals['CIS564'] = 'Hacking Technic'; 

echo 'You have a total of '. count($Globals) .' courses now!'; 

Answer 3

这里在代码中有解释的答案

<?php 

    $Globals = []; 
    $counter = 0; 

    /** 
    * @param array $course 
    * @param string $courseCode 
    * @param string $courseName 
    * @param int $counter 
    * 
    * @return array 
    */ 
    function array_push_assoc($course, $courseCode, $courseName, $counter){ 
     $course[$courseCode] = $courseName; 

     // inside a function, you cannot use a global variable, you have to get it as argument and return it 
     $counter++; 

     // do the return at the end of the function because nothing else is performed after this 
     return array(
      $course, 
      $counter 
     ); 
    } 

    list($Globals, $counter) = array_push_assoc($Globals, 'CIS370', 'Introduction to Web Development', $counter); 
    list($Globals, $counter) = array_push_assoc($Globals, 'CIS475', 'Advance Web Development', $counter); 
    list($Globals, $counter) = array_push_assoc($Globals, 'CIS560', 'Introduction to Syber Security', $counter); 
    list($Globals, $counter) = array_push_assoc($Globals, 'CIS564', 'Hacking Technic', $counter); 

    // use double quotes "" if you want $counter to be echoed as the value of the variable $counter, not the word '$counter' 
    echo "You have a total of $counter courses now!"; 
    // it is good practice to add a line break, this improves the script output 
    echo PHP_EOL; 
?>