这个类取自Marijn Havereke 的书 Eloquent JavaScript怎么样?
小提琴
function Dictionary(values) {
this.values = values || {};
var forEachIn = function (object, action) {
for (var property in object) {
if (Object.prototype.hasOwnProperty.call(object, property))
action(property, object[property]);
}
};
Dictionary.prototype.containsKey = function(key) {
return Object.prototype.hasOwnProperty.call(this.values, key) &&
Object.prototype.propertyIsEnumerable.call(this.values, key);
};
Dictionary.prototype.forEach = function(action) {
forEachIn(this.values, action);
};
Dictionary.prototype.lookup = function(key) {
return this.values[key];
};
Dictionary.prototype.add = function(key, value) {
this.values[key] = value;
};
};
var numberDic = new Dictionary({One: 1,Two: 2, Three: 3});
//-- does key exist
console.log(numberDic.containsKey("One"));
console.log(numberDic.containsKey("One"));
console.log(numberDic.containsKey("Four"));
//-- loop through each item in the dic
numberDic.forEach(function(key, value) {
console.log(key, "is", value);
});
//-- works with complex objects
//------------------------------------------
var complexObjectDic = new Dictionary({
Microsoft: {
Something: "Real Interesting",
About: "Microsoft",
Will: "Go",
Here: ".",
ProductPrices: {
WindowsPhone: 55.88,
Windows :{
WinXp : 180.00,
Win7 : 200.00,
Win8 : 150.00
}
}
},
Apple: {
Did: "you",
Hear: "the",
New: "iphone",
Will: "be coming out soon",
}});
//-- does key exist
console.log(complexObjectDic.containsKey("Microsoft"));
console.log(complexObjectDic.containsKey("Apple"));
console.log(complexObjectDic.containsKey("Facebook"));
//-- search the dic by key
console.log(complexObjectDic.lookup("Microsoft"));
console.log(complexObjectDic.lookup("Apple"));
//-- add item to dic
complexObjectDic.add("Instagram", {
This: "is",
Another: "object",
That: "I willl be Adding"
});
//-- loop through each item in the dic
complexObjectDic.forEach(function(key, value) {
console.log(key, value);
});