The Array.prototype.forEach() method allows each item in the array to execute the given function once. — MDN
Suppose there is such a scenario and you get such an array
[
{ symbol: "XFX", price: 240.22, volume: 23432 },
{ symbol: "TNZ", price: 332.19, volume: 234 },
{ symbol: "JXJ", price: 120.22, volume: 5323 },
]
You need to create a new array for the symbols in it, that is
[ "XFX", "TNZ", "JXJ"]
Generally this can be achieved using a for loop:
function getStockSymbols(stocks) { var symbols = [], stock, i; for (i = 0; i < stocks.length; i++) { stock = stocks[i]; symbols.push(stock.symbol); } return symbols; } var symbols = getStockSymbols([ { symbol: "XFX", price: 240.22, volume: 23432 }, { symbol: "TNZ", price: 332.19, volume: 234 }, { symbol: "JXJ", price: 120.22, volume: 5323 }, ]);
Output: "[/"XFX/", "TNZ/", "JXJ/"]"
You can also use Array’s forEach method to simplify the code. Their output is exactly the same.
function getStockSymbols(stocks) { var symbols = []; stocks.forEach(function(stock) { symbols.push(stock.symbol); }); return symbols; }