It has been done to death pretty much, here on SO and around the 'Net. However I was wondering if there was a way to leverage the standard min/max functions of:
Array.max = function(array) {
return Math.max.apply(Math, array);
};
Array.min = function(array) {
return Math.min.apply(Math, array);
};
So I can search across an array of objects of say:
function Vector(x, y, z) { this.x = x; this.y = y; this.z = z; }
var ArrayVector = [ /* lots of data */ ];
var min_x = ArrayVector.x.min(); // or
var max_y = ArrayVector["y"].max();
Currently I have to loop through the array and compare the object values manually and craft each one to the particular need of the loop. A more general purpose way would be nice (if slightly slower).
-
You could make some changes to your
Array.minandmaxmethods to accept a property name, extract that property of each object in the array, with the help ofArray.prototype.map, and the max or min value of those extracted values:Array.maxProp = function (array, prop) { var values = array.map(function (el) { return el[prop]; }); return Math.max.apply(Math, values); }; var max_x = Array.maxProp(ArrayVector, 'x');I just want to mention that the
Array.prototype.mapmethod will be available on almost all modern browsers, and it is part of the ECMAScript 5th Edition Specification, but Internet Explorer doesn't have it, however you can easily include an implementation like the found on the Mozilla Developer Center.graham.reeds : That is quite an elegant solution. I can see it constructs an new temporary array so I will probably have to cache it, or use it sparingly.
0 comments:
Post a Comment