使用javascript在json数据中搜索一个键

Question

data:{
key1:{
   child1:{},
   child2:{}
 }
key2:{
  child21:{}
 }
}

how can I get key2's child when i am not sure about key2's position?

Answer 1

var keys = Object.keys(data);

This will return an array of strings of the key names. ["key1", "key2"]

I think specifically you need:

var childnames = Object.keys(data[key2]);

You could turn this into an array of those objects that are it's children by:

var key2children = [];
for(var i=0; i< childnames.length; i++){
  key2children.push(data[key2][cildnames[i]);
}

EDIT Maybe this helps?:

//To get the children of an object
function getChildObjects(tgtobj){
    var objchildren = [];
    objectkeys = Object.keys(tgtobj);
    for(var i=0; i< objectkeys.length; i++){
      key2children.push(tgtobj[objectkeys[i]);
    }
    return objectchildren;
}

//This could be used to get the children of a child object in a function like this:
function getChildOjectsOfChildByName(tgtobj, name){
    return getChildObjects(tgtobj[name]);
}

//usage example:
var key2childojects = getChildOjectsOfChildByName(data, "key2");

Answer 2

You would have to use a for in loop and recursion to get the nested key.

function searchObj(obj, searVal){
    for (ii in obj){
        if(ii === searVal){
            console.log(ii, ' -- my key');
        } else{
            console.log(ii, ' -- no key here');
            searchObj(obj[ii], searVal);
        }
    }
}
searchObj(data, 'child21');