Question

I have a data structure similar to this ->

var prices = [
    {currency: '$', value: 52},
    {currency: '$', value: 139},
    {currency: '$', value: 31},
    {currency: '$', value: 5}
];

I want to know the highest price from that data. I know I can loop over the array and collect the data, but what would be the best way of doing it ?

Answer 1

We can do this pretty neat by using Array.prototype.map alongside Math.max. Since .map() returns an Array, we can use that to invoke Math.max by Function.prototype.apply. The result would look like

var max = Math.max.apply(null, prices.map(function( entry ) {
    return entry.value;
}));

console.log( max ); // 139

---

The above statement equals

Math.max( 51, 139, 31, 5 );

which would return the same result, we just created it programatically.