V8 hidden class benchmark

hidden-classes.js

// 10m
var times = 10000000;


var n = times
  , start = new Date;
while (n--) {
  var point = [50,100];
  point[0];
  point[1];
}
console.log('array: %sms', new Date - start);

function Point(x, y){
  this.x = x;
  this.y = y;
}

var n = times
  , start = new Date;
while (n--) {
  var point = new Point(50, 100);
  point.x;
  point.y;
}
console.log('Point: %sms', new Date - start);

var n = times
  , start = new Date;
while (n--) {
  var point = { x: 50, y: 100 };
  point.x;
  point.y;
}
console.log('Object: %sms', new Date - start);

stdout

array: 161ms
Point: 135ms
Object: 275ms
C Point: 21.6ms

test.c

#include <stdio.h>
#include <time.h>

typedef struct {
  double x;
  double y;
} Point;

int
main(int argc, const char **argv){
  int n = 10000000;
  clock_t start = clock();
  while (n--){
    Point p = { 50, 100 };
    p.x;
    p.y;
  }
  printf("C Point: %.2fms\n", ((float)(clock() - start) / CLOCKS_PER_SEC) * 1000);
  return 0;
}