如何修改数组中的每个第n项？

Question

我试图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,仅将每个第五项修改为[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]"

这就输出了

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] prefix [ 3R]

Answer 1

使用"for" 从4开始(数组的第5个元素)并逐步增加5:

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.