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Home Backend Development PHP Tutorial 请问 关于字数组的问题

请问 关于字数组的问题

Jun 23, 2016 pm 01:31 PM

请问


$test = array();
function abc($port, $index = 0){
if (!isset($GLOBALS['test'][$index]))
$GLOBALS['test'][$index] = array();
$GLOBALS['test'][$index]  [] = $port;
}

?>

请问 以上代码中  而原先在函数外定义test是一维数组的,
但是$GLOBALS['test'][$index]  [] = $port; 这样test就变成了  2维数组了。 
那么  能不能理解为  这个数组的 一行中有多少个数据 有   $port决定,即 $port如果是3,那么这个
数组的一行就是有三个数据。  是这样吗?  麻烦会的朋友帮忙回复下,谢啦


回复讨论(解决方案)

php 的数组不是传统意义上的数组
只在是二维数组时,勉强可附会行和列的概念

php 的数组不是传统意义上的数组
只在是二维数组时,勉强可附会行和列的概念



谢谢  xuzuning 版主的回复

还想请问下  那么 $GLOBALS['test'][$index] [] = $port;  这句话应该怎么理解呢?

$GLOBALS['test'][$index] [] = $port;
等于
array_push($GLOBALS['test'][$index],$port);

$GLOBALS['test'][$index] [] = $port;
等于
array_push($GLOBALS['test'][$index],$port);



谢谢  fdipzone 版主的回复

但是我还有些地方不太明白。

比如说    $port = 1;
那么当运行 $GLOBALS['test'][$index] [] = $port;的时候, 那么这时候  $GLOBALS['test'][$index] []  里边的
$GLOBALS['test'][$index]  [0]  为1 ,是这样吗?。也就是说 它就是2维数组。 或者说 能理解为 它是2为数组吗。


$GLOBALS['test'][$index] [] = $port;
等于
array_push($GLOBALS['test'][$index],$port);



谢谢  fdipzone 版主的回复

但是我还有些地方不太明白。

比如说    $port = 1;
那么当运行 $GLOBALS['test'][$index] [] = $port;的时候, 那么这时候  $GLOBALS['test'][$index] []  里边的
$GLOBALS['test'][$index]  [0]  为1 ,是这样吗?。也就是说 它就是2维数组。 或者说 能理解为 它是2为数组吗。


是的,你print_r 打印出来看看就知道了。
$GLOBALS['test'][$index] [0]  其实这样已经是多维数足组了。

真有本事,非要把简单的事情弄复杂了

$test = array();
$port = 1;

$GLOBALS['test'][$index] [] = $port;
将 $port 追加到数组 $GLOBALS['test'][$index] 中
即 将 $port 追加到数组 $test[$index] 中
完成后
$GLOBALS['test'] 是3维数组
$test 是2维数组

之所以说 php 的 array 不是传统意义的数组,是因为数组是齐次的,即每行的列数相同
而 php 的 array 就没有这个约束 array(array(1,2,3), array(4))
另外标记数组元素位置的值连续数字,而 php 的 array 也没有这个约束 array(3 => array(1,2,3), 8 => array(4))
还可以使用名称(关联键)标记 array('c' => array(1,2,3), array(4))

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