RosettaCodeData/Task/Reflection-List-methods/JavaScript/reflection-list-methods.js

86 lines
2.4 KiB
JavaScript

// Sample classes for reflection
function Super(name) {
this.name = name;
this.superOwn = function() { return 'super owned'; };
}
Super.prototype = {
constructor: Super
className: 'super',
toString: function() { return "Super(" + this.name + ")"; },
doSup: function() { return 'did super stuff'; }
}
function Sub() {
Object.getPrototypeOf(this).constructor.apply(this, arguments);
this.rest = [].slice.call(arguments, 1);
this.subOwn = function() { return 'sub owned'; };
}
Sub.prototype = Object.assign(
new Super('prototype'),
{
constructor: Sub
className: 'sub',
toString: function() { return "Sub(" + this.name + ")"; },
doSub: function() { return 'did sub stuff'; }
});
Object.defineProperty(Sub.prototype, 'shush', {
value: function() { return ' non-enumerable'; },
enumerable: false // the default
});
var sup = new Super('sup'),
sub = new Sub('sub', 0, 'I', 'two');
Object.defineProperty(sub, 'quiet', {
value: function() { return 'sub owned non-enumerable'; },
enumerable: false
});
// get enumerable methods on an object and its ancestors
function get_method_names(obj) {
var methods = [];
for (var p in obj) {
if (typeof obj[p] == 'function') {
methods.push(p);
}
}
return methods;
}
get_method_names(sub);
//["subOwn", "superOwn", "toString", "doSub", "doSup"]
// get enumerable properties on an object and its ancestors
function get_property_names(obj) {
var properties = [];
for (var p in obj) {
properties.push(p);
}
return properties;
}
// alternate way to get enumerable method names on an object and its ancestors
function get_method_names(obj) {
return get_property_names(obj)
.filter(function(p) {return typeof obj[p] == 'function';});
}
get_method_names(sub);
//["subOwn", "superOwn", "toString", "doSub", "doSup"]
// get enumerable & non-enumerable method names set directly on an object
Object.getOwnPropertyNames(sub)
.filter(function(p) {return typeof sub[p] == 'function';})
//["subOwn", "shhh"]
// get enumerable method names set directly on an object
Object.keys(sub)
.filter(function(p) {return typeof sub[p] == 'function';})
//["subOwn"]
// get enumerable method names & values set directly on an object
Object.entries(sub)
.filter(function(p) {return typeof p[1] == 'function';})
//[["subOwn", function () {...}]]