function getStockSymbols(stocks){

  var symbols = [];

  var counter;

  for (counter= 0; counter < stocks.length; counter++){

    stock = stocks[counter];

    symbols.push (stock.symbol);

  }

  return symbols;

}

​

​

​

​

var symbols = getStockSymbols([

  {symbol :"XYZ", price : 240.22, volumne : 23434},

  {symbol :"TRE", price : 340.22, volumne : 33434},

  {symbol :"POI", price : 440.22, volumne : 43434}

]);

​

console.log(JSON.stringify(symbols));