Question

我正在尝试找到最有效的方法来获取数组中的每个第五项，然后使用str_replace修改它。

例如，每隔五个项目修改[3r]至[4r]。

$ myArray = array（“apples [3r]”，“jacobs [3r]”，“chocolate [3r]”，“makeup [3r]”，“lipstick [3r]”，“triangle [3r]”， “jacobson [3r]”，“lacksasf [3r]”，“dahe [3r]”，“applestoapples [3r]”，“coaxale [3r]”，“hamburger [3r]”，“前缀[3r]”

这是输出

苹果[3r] jacobs [3r]巧克力[3r]化妆[3r]唇膏[4r]三角形[3r] jacobson [3r] lacksasf [3r] dahe [3r] applestoapples [4r] coaxale [3r] hamburger [3r] ]前缀[3r]

Answer 1

使用“for”从4开始（数组的第5个元素）并逐步增加5个：

for ($i = 4; $i < count($myArray); $i += 5) {
    $myArray[$i] = str_replace('[3r]', '[4r]', $myArray[$i]);
}

编辑：我忘了再次将结果分配给数组。

Answer 2

for ($i = 0; $i*5+4 < sizeof($myArray); $i++) {
    $myArray[$i*5+4] = str_replace("[3r]","[4r]", $myArray[$i*5+4]);
}

Answer 3

for( $i=0;$i<count( $array );$i+=<N-1> ){
   ...
}

使用for循环并每次添加N-1

Answer 4

$myArray = array("apples[3r]", "jacobs[3r]", "chocolate[3r]", "makeup[3r]", "lipstick[3r]", "triangle[3r]", "jacobson[3r]", "lacksasf[3r]","dahe[3r]", "applestoapples[3r]", "coaxale[3r]", "hamburger[3r]", "prefix[3r]");

$len = count($myArray);
$total = floor($len/5);
$count = 5;
for($i=0, $i<= $total, $i++) {
    $myArray[$count] = str_replace("[3r]", "[4r]", $myArray[$count]);
    $count += 5;
}

Answer 5

只是迭代你的数组但只改变每个fith项：

$i = 0;
foreach ($myArray as &$value)
{
    if ($i++ % 5) continue;   
    $value = str_replace(/* lookup the manual if you don't know this function */);
}
unset($value);

如果您不想在0使用$i初始化-4时开始统计。

Answer 6

这将进行此更改：

$myArray = array(
  "apples[3r]", 
  "jacobs[3r]", 
  "chocolate[3r]", 
  "makeup[3r]", 
  "lipstick[3r]", 
  "triangle[3r]", 
  "jacobson[3r]", 
  "lacksasf[3r]",
  "dahe[3r]", 
  "applestoapples[3r]", 
  "coaxale[3r]", 
  "hamburger[3r]", 
  "prefix[3r]"
);

$sizeMyArray = count($myArray);

for ($i = 4; $i < $sizeMyArray; $i+= 5) {
  $myArray[$i] = str_replace('[3r]', '[4r]', $myArray[$i]);
}

print_r($myArray);

/* Array ( 
 * [0] => apples[3r] 
 * [1] => jacobs[3r] 
 * [2] => chocolate[3r] 
 * [3] => makeup[3r] 
 * [4] => lipstick[4r] 
 * [5] => triangle[3r] 
 * [6] => jacobson[3r] 
 * [7] => lacksasf[3r] 
 * [8] => dahe[3r] 
 * [9] => applestoapples[4r] 
 * [10] => coaxale[3r] 
 * [11] => hamburger[3r] 
 * [12] => prefix[3r] ) */

如何修改数组中的每个第n项？

6 个答案: