使用array_filter函数，可以获取couponCode值不等于594的项目

$json = json_decode('[
    {
      "couponCode": "GanheOutro",
      "description": "Ganhe Outro",
      "status": "Active",
      "type": "EarnedProduct",
      "validProducts": {
        "posCodes": [
          "I11009",
          "I22749"
        ]
      },
      "limitedQuantity": 1,
      "couponRequired": 1,
      "discountCode": 378,
      "discountInfo": ""
    },
    {
      "couponCode": 593,
      "description": "Bebida de Aniversário",
      "status": "Active",
      "type": "Discount",
      "discount": 1,
      "limitedQuantity": 1,
      "couponRequired": 1,
      "discountCode": 247,
      "discountInfo": ""
    },
    {
      "couponCode": 594,
      "description": "Bebida 12 Estrelas",
      "status": "Active",
      "type": "Discount",
      "discount": 1,
      "limitedQuantity": 1,
      "couponRequired": 1,
      "discountCode": 248,
      "discountInfo": ""
    }
  ]');

$result = array_filter($json, fn ($item) => $item->couponCode !== 594);

var_export($result);

以下是一些指导原则：
可以使用PHP中的array_filter函数来过滤数组并移除所需的元素。
array_filter函数有两个参数：原始数组和回调函数。如果元素应保留在过滤数组中，则回调函数应返回true;如果应删除该元素，则回调函数应返回false。在这种情况下，应使用匿名函数检查当前元素的couponCode是否不等于594。
(ofc为了完成所有这些，您应该首先将json数据放入一个数组中）