min and max value prototype for array of object

minMax.js

Array.prototype.min = function() {
  var self = this, p = arguments[0];
  
  return self
  .filter(f => p.zero === false ? f[p.prop] > 0 : f)
  .map(m => m[p.prop])
  .reduce((a, c) => {
    return a = (a === undefined || c < a) ? c : a
  });
}

Array.prototype.max = function() {
  var self = this, p = arguments[0];
  
  return self
  .filter(f => f[p.prop] > 0)
  .map(m => m[p.prop])
  .reduce((a, c) => {
    return a = (a === undefined || c > a) ? c : a
  });
}