javascript类声明之间的区别

Question

I was trying to create a module for node.js and i noticed something. Example

function Example() {
     this.property = "something";

}

Example.prototype.run = function() {
     console.log('hello world')
}

module.exports = Example;

with this code it say's that there's no method run. I need it to declare like

Example.prototype.run = function run() {}

to work. Why is that happening ?

Answer 1

This should work fine as long as you actually call the constructor and create an object which is how you've configured the Example code:

var Example = require("./example");
var item = new Example();
item.run();

Answer 2

You need to load the module and instantiate the Example class.

Example.js :

function Example() {
    this.property = "something";
}

Example.prototype.run = function() {
    console.log('hello world')
}

module.exports = Example;

main.js :

var Example = require("./Example.js");
var example = new Example();
example.run();

run:

$ node main.js
hello world