PHP json_encode - 奇怪的行为

Using json_encode对日期数组进行编码，它有时会做一件事，有时会做另一件事。

例如，如果我尝试编码如下内容：

array(6) {
  [0]=>
  string(6) "Jun-24"
  [1]=>
  string(6) "Jun-25"
  [2]=>
  string(6) "Jun-28"
  [3]=>
  string(11) "Training-24"
  [4]=>
  string(6) "Jun-29"
  [5]=>
  string(6) "Jun-30"
}

它将输出

["Jun-24","Jun-25","Jun-28","Training-24","Jun-29","Jun-30"]

但是，当我尝试编码如下内容时：

array(17) {
  [0]=>
  string(6) "Jun-23"
  [1]=>
  string(6) "Jun-24"
  [2]=>
  string(6) "Jun-28"
  [3]=>
  string(11) "Training-24"
  [4]=>
  string(6) "Jun-29"
  [5]=>
  string(6) "Jun-30"
  [6]=>
  string(6) "Jul-06"
  [7]=>
  string(6) "Jul-07"
  [9]=>
  string(6) "Jul-09"
  [10]=>
  string(6) "Jul-16"
  [11]=>
  string(6) "Jul-17"
  [12]=>
  string(6) "Jul-20"
  [13]=>
  string(6) "Jul-23"
  [14]=>
  string(6) "Jul-24"
  [15]=>
  string(6) "Jul-30"
  [16]=>
  string(6) "Aug-01"
  [17]=>
  string(6) "Aug-05"
}

它将输出

{"0":"Jun-23","1":"Jun-24","2":"Jun-28","3":"Training-24","4":"Jun-29","5":"Jun-30","6":"Jul-06","7":"Jul-07","9":"Jul-09","10":"Jul-16","11":"Jul-17","12":"Jul-20","13":"Jul-23","14":"Jul-24","15":"Jul-30","16":"Aug-01","17":"Aug-05"}

（抱歉，找不到失败的较小示例）

重点是，它为什么这样做？选项相同，数组结构相同，有什么问题？

您的 PHP 数组缺少条目 8，因此是映射（对象）而不是列表（数组）。