[Javascript] The Array map method

One very common operation in programming is to iterate through an Array's contents, apply a function to each item, and create a new array containing the results. For example, let's say you wanted to loop through an array of stock objects and select only the name for display on screen. In this lesson we will demonstrate how to use the Array's map method to easily perform this operation with less code than a loop would require.

function getStockSymbols(stocks) {
  return stocks.map(function(stock) {
    return stock.symbol;
  })
}

var symbols = getStockSymbols([
  { symbol: "XFX", price: 240.22, volume: 23432 },
  { symbol: "TNZ", price: 332.19, volume: 234 },
  { symbol: "JXJ", price: 120.22, volume: 5323 },
]);

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