get previous json item in Json-CodePudding

I have a JSON file titled stuff.json. I am trying to get the previous json item given a certain item. For example, if I am given the key ["also-random-here"], how do I get the previous JSON item "sample-name"?

My JSON data looks as follows:

{
    "random-name-here": {
        "name": "name is item1"
    },
    "sample-name": {
        "name": "name is item2"
    },
    "also-random-here": {
        "name": "name is item3"
    }
}

CodePudding user response：

try this

var names={
    "random-name-here": {
        "name": "name is item1"
    },
    "sample-name": {
        "name": "name is item2"
    },
    "also-random-here": {
        "name": "name is item3"
    }
};
    var prevName= findPrevName(names, "also-random-here") ;

  function findPrevName(item, key) {
      var prevName;
  for (const property in item)
  {
        if(property==key)  break;
       prevName=property;
  };

     return  { [prevName]: item[prevName]};
  };