above, promise itself is an event publish/subscribe model.So the three functions above then are equivalent to the event binding function. (is the observer)When the previous task is deferred.resolve (data), corresponding to this task will trigger the Onfulfilled method.When the previous task is deferred.reject (err), the corresponding task will trigger the Onrejected method.Any one task, the onfulfilled or Onrejected method can only be triggered one, and is triggered once.The last catch in our m
node. JS callback functionThe callback function generally appears as the last parameter of the function:function foo1 (name, age, callback) {}function Foo2 (value, Callback1, Callback2) {}Blocking Code InstancesCreate a file input.txt with the following content:Beginner's Tu
Blocking call and non-blocking call of node. js callback Functions
First, node. as a javascript running platform, js adopts event-driven and asynchronous programming methods. Through event registration and asynchronous functions, developers can improve resource utilization
Jintiansheng: To learn a new thing, it is necessary to hold a hug mentality, if cling to their previous concept system, there will be a difficult feeling.. NET programmer first with node. JS is the most need to adapt to asynchronous development, all asynchronous, the general logic of the traversal of the list is asynchronous, how to ensure that the list traversal execution is complete? Promise help you get
1. Create a input.txt text file and write something inside.2. Create a Main.js fileVarfs = require("FS"); var data = fs. Readfilesync('input.txt'); (This place must be prefixed with the name of the suffix)console. Log(data. ToString()); console. Log("program execution ends!") ); 3. The results of the code above for synchronization are as follows:$ node main. JS Rookie Tutorial official website address
The immediate manifestation of node. JS asynchronous programming is callbacks.Asynchronous programming relies on callbacks to implement, but can not say that the use of callbacks after the program is asynchronous, the callback function will be called after the completion of the task, node uses a large number of
This article mainly introduces how to use Meteor with Node. js Code example of real-time chat application, Node. as an asynchronous framework, js is used to compile real-time applications. For more information, see Derby. the framework for
This article mainly introduces Node. examples of simple web page capturing functions implemented by js. This article uses libraries such as PhantomJS and node-phantomjs to implement these functions. For more information, see the following: web page capturing is a well-known technology, however, there are still a lot of complexities. Simple Web crawlers are still
Example of using Node. js to implement RESTful API, node. jsrestful
Basic RESTful concepts
REST (Representational State Transfer) describes an architecture-style network system that first appeared in Roy Fielding's doctoral thesis in 2000. In the REST service, application status and functions can be divided into variou
Here we will share with you node. examples of js operations on the mongoDB database, including connecting to the database, inserting data, closing the database, reading data, and inserting data, are very comprehensive. We recommend this to our partners.
Connect to database
The Code is as follows:
Var mongo = require ("mongodb ");Var host = "localhost ";Var port = mongo. Connection. DEFAULT_PORT;Var serve
This article mainly introduces a simple node. js server example. This article implements a simple helloworld example and shows how to run this server, for more information, see the following example: hello world.
It seems that the first section of each language tutorial w
This article mainly introduces Node. example of calling the mysql stored procedure in js. this article passes the test in the windows environment. This article also provides examples of creating a database, inputting data, creating a stored procedure, and calling a stored procedure, for more information, see the example
This article mainly introduces node. the js [superAgent] request usage example summarizes the post request, get request, delete request, and put request examples, and recommends them to you. Post request:
The code is as follows:
Request. post ('/api/pet '). End (function (resp, err ){If (resp. body. status === 200 ){Alert ('Yay got '+ JSON. stringify (res.
Node. js is a simple example of checking whether a port is occupied. node. jsport
Preface
In network technology, a Port has two meanings: one is a physical Port, for example, ADSL Modem, Hub, switch, router is used to connect other network equipment interface, such as RJ-45
A callback function is a function called by a function pointer. The following example shows how to use a callback function: a callback function is a function called by a function pointer. If you pass the pointer (address) of a function as a parameter to another function, when this pointer is used to call the function t
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