php获取下面json字符串中内容

Question

麻烦写个示例，居于下面的json字符串

如何才能取到params 中 title ，value属性值和对应params中的的value属性值。

$hdmc='[{"id":"radios","type":"radios","name":"单选","params":{"title":"赠品","value":"大米一袋","explain":"","required":true},"style":{},"data":[{"name":"身爱之物玻色因奢护十件套"},{"name":"大米一袋"},{"name":"小米一袋"},{"name":"石油一同"}],"_sortId":"1667279616767_0.36685411348863206"},{"id":"singlelinetext","type":"singlelinetext","name":"单行文本","params":{"title":"请输入领取员工工号（可向店员获取）","value":"1831","explain":"","required":true,"tip":"数字工号"},"style":{},"data":[],"_sortId":"1667279260378_0.04160550388526385"}]';