知道key的話簡單，不知道那些key是數(shù)組的話

var aa = [{a:1,b:1,c:[{aa:1},{bb:1},{cc:1}]},{a:2,b:2,c:[{dd:2},{ee:2},{ff:2}]}]
var bb = [];
    for(var i in aa){
       for(var j in aa[i]){
           if(typeof aa[i][j] === 'object'){
            bb.push(...aa[i][j]);  //bb = bb.concat(aa[i][j]);   bb = [...bb,...aa[i][j]];
           };
       }
    }
   console.log(bb);

function filter(arr){
    var ret = [];
    for(var i=0; i<arr.length; i++){
        if(arr[i].c){
            ret = ret.concat(arr[i].c);
        }
    }
    return ret;
}

var aa = [{a:1,b:1,c:[{aa:1},{bb:1},{cc:1}]},{a:2,b:2,c:[{dd:2},{ee:2},{ff:2}]}];
var arr = [];
for(var a in aa)
    arr.push(aa[a].c);
console.log(arr);