集合属性封装
function Set() {
this.items = {}
}
add方法
Set.prototype.add = function (value) {
if (this.has(value)) return false
this.items[value] = value
return true
}
has方法
Set.prototype.has = function (value) {
return this.items.hasOwnProperty(value)
}
remove方法
Set.prototype.remove = function (value) {
if (!this.has(value)) return false
delete this.items[value]
return true
}
size方法
Set.prototype.size = function () {
return Object.keys(this.items).length
}
clear方法
Set.prototype.clear = function () {
this.items = {}
}
values方法
Set.prototype.values = function () {
return Object.keys(this.items)
}
unions方法
Set.prototype.unions = function (otherSet) {
var unionSet = new Set()
var values = this.values()
for (var i = 0; i < values.length; i++) {
unionSet.add(values[i])
}
values = otherSet.values()
for (i = 0; i < values.length; i++) {
unionSet.add(values[i])
}
return unionSet
}
intersection方法
Set.prototype.intersection = function (otherSet) {
var values = this.values()
var intersectionSet = new Set()
for (var i = 0; i < values.length; i++) {
var item = values[i]
if (otherSet.has(item)) {
intersectionSet.add(item)
}
}
return intersectionSet
}
difference方法
Set.prototype.difference = function (otherSet) {
var values = this.values()
var diffSet = new Set()
for (var i = 0; i < values.length; i++) {
var item = values[i]
if (!otherSet.has(item)) {
diffSet.add(item)
}
}
return diffSet
}
subset方法
Set.prototype.subset = function (otherSet) {
var values = this.values()
for (var i = 0; i < values.length; i++) {
var item = values[i]
if (!otherSet.has(item)) {
return false
}
return true
}
}
