Port Java HashMap functionality to JavaScript
npm install java-hashmapshell
$ npm install -g npm
$ npm install java-hashmap
`
In Node.js:
js
const HashMap = require("java-hashmap");
`Creating a HashMap
The HashMap package returns a class, you can use this class to create a HashMap. For example, here is one of character colors:
js
const HashMap = require("hashmap");
var characterColors = new HashMap();
`Interact with data
There isn't much use to a HashMap if you can't even deal with the information in it, so let's look at that.$3
To add data to the HashMap, use the .put()` method. It takes two parameters, the key and the value.
`js
characterColors.put("Sonic", "blue");
characterColors.put("Mario", "red");
characterColors.put("Ryu", "white");
`$3
To remove data from the HashMap, use the .remove()` method. It takes one parameter, the key.
`js
characterColors.remove("Sonic");
characterColors.remove("Mario");
characterColors.remove("Ryu");
`$3
To clear all the data from the HashMap, use the .clear()` method.
`js
characterColors.clear();
`Reading data
The ability to modify data is no good if you can't even read it. So, there are a lot of methods with HashMaps for reading data.$3
To get a value by it's associated key, use the .get()` method. It takes one parameter, the key.
`js
characterColors.get("Sonic");
characterColors.get("Mario");
characterColors.get("Ryu");
`$3
To get all the data in the form of two Arrays, use the .get()` method without supplying any parameters.
`js
characterColors.get();
`$3
To get all the keys, use the .keySet()` method.
`js
characterColors.keySet();
`$3
To get all the values, use the .values()` method.
`js
characterColors.values();
`$3
To get all the size of the HashMap, use the .size()` method.
`js
characterColors.size();
`Generate HashMap from Object/Array
Sometimes it's useful to generate a HashMap from an Object or an Array, to do so use the .generate()` method.
`js
const characterColors = new HashMap();//With one Object
characterColors.generate({
Sonic: "blue",
Mario: "red",
Ryu: "white"
});
/*["Sonic", "Mario", "Ryu"]
["blue", "red", "white"]*/
//With two Arrays
characterColors.generate(
["Sonic", "Mario", "Ryu"],
["blue", "red", "white"]);
/*["Sonic", "Mario", "Ryu"]
["blue", "red", "white"]*/
//With one Array
characterColors.generate(["Sonic", "Mario", "Ryu"]);
/[0, 1, 2], ["Sonic", "Mario", "Ryu"]/
``