lable end. Output lable:100ms (can calculate intermediate processing time) console.timeend (' lable '); Prints information about the current stack lable. Output trace:lable---------------------- console.trace (' lable '); Assertion syntax: Console.assert (Expression,[message]) //output assertionerror: Abnormal Console.assert (false, ' abnormal slightly ');V. BufferThe appearance of this buffer is basically to solve the situation that JS
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Use setTimeout to delay function execution
Use clearTimeout to cancel an execution plan
Develop and cancel repeated execution plans for Functions
Use process. nextTick to delay function execution to the next round of the event Loop
Congestion event Loop
Exit event Loop
Use setTimeout instead of setInterval to ensure the serialization of function execution
For the list of articles in this series and the translation progress, see
something you should worry about unless you record huge amounts of data.Console.log ([data], [...])Prints another line to the standard output. This function can use printf () to take multiple parameters in a similar way. For example:1 console.log (' Count:%d ', count);If the first string argument is not a formatted string, Util.inspect is applied to each parameter. See Util.format ()for more information.In fact, when encountering the first parameter that cannot be passed into a formatted string
"]==data["id"]) {Con[i]=data; Flag=true; Break; }} result.msg= "The modification failed, the customer needs to be modified does not exist"; if(flag) {Fs.writefilesync (Custompath,json.stringify (con),"Utf-8"); Result={code:0, msg:"Modified successfully"}} res.writehead (200,{' content-type ': ' Application/json;charset=utf-8; '}); Res.end (json.stringify (result)); }) return; } //If the requested address is not one of these, the prompt does not existRes.writehead (404,{' conten
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Create a buffer
Obtain and set buffered data
Split and buffer data
Copy buffered data
Decodes buffered data
For the list of articles in this series and the translation progress, see Node. js advanced programming: using Javascript to build scalable applications (〇)
This article corresponds to the original article Part 2 Chapter 4: Node
(writablestream)
reads data from Readablestream and sends it to Writablestream. When writablestream.write (data) returns false,readablestream pauses until writablestream occurs Drain event. Callback has an error as its only parameter and is called when the Writablestream is closed or when an error occurs. Util.inherits (constructor, Superconstructor)inherit a method from a prototype to another constructor from one of the constructor functions. The constructor prototype will be set to a new
:...True2. Invocation of functionsThis points to the global object in the execution environment (browser->window nodejs->global)function Pet2 (words) {This.words = wordsConsole.log (This.words)Console.log (This===global)}Pet2 (' ... ')Printing results:...True3. ConstructorsThis method is called by the instance object, which points to this instance objectfunction PEt3 (words) {This.words = wordsThis.speak = function () {Console.log (This.words)Console.log (This)}}var cat = new PEt3 (' Miao ')Prin
], [...])after I/O event callbacks are scheduled, the callbackis executed "immediately" beforesetTimeout and setinterval . Returns a immediateobject for clearimmediate () to use when needed. Optionally, you can pass parameters to the callback function. The immediate events are placed in the queue in the order in which they were created, and one pops up from the queue header in each iteration of the event loop. This is different from Process.nexttick , which executes the callback function in the
1. Install node, NPM2. Installing StrongloopNPM install-g--unsafe-perm Install Strongloop3. Create a working directory and configure the loopback appmkdir Todos CD TODOSSLC loopbackThe installation will appear successfully Change the directory to your application $ cd yourrestful in the application to create the model $ SLC Loopback:model Run application $ node.4. Install MySQLInstall loopback-
: '/submit' , method: 'post' }; var Req = http. request (options, function (RES) {res. setencoding ( 'utf8' ); Res. on ( 'data', function (chunk) {console. log ( 'body: '+ chunk) ;}); req. write ( "my data" ); req. write ( "more of my data" ); req. end ();
In the above example, we use the req. Write () method to describe the data we want to send to the server, and finally use Req. End () to initialize and send a request. The res in the Code is a clientresponse object. It has two im
I/O is a very important part that distinguishes node from other frameworks. This chapter will explain how it achieves node non-blocking I/O.
Streams
Stream API is an abstract interface that helps many parts of node perform uninterrupted input and output operations. Stream API
); Console.log (Buf.readint16le (0)); 12Copy (Targetbuffer,[targetstart],[sourcestart],[sourceend]) copies the specified position from a buffer object to the target buffer var sbuffer = new Buffer ("Lone Orphan"); var tBuffer1 = new Buffer (6); var tBuffer2 = new Buffer (9); Sbuffer.copy (tBuffer1); Sbuffer.copy (tBuffer2); Console.log (Tbuffer1.tostring ()); Solitary Console.log (tbuffer2.tostring ()); Lone Lonely Beg You can see that there is no above, with a com
considered node-specific, because it is a platform for large-scale application-level asynchronous IO applications, which strives to allocate resources more efficiently on a single thread.
About PromiseHere, this article does not intend to explain the use of promise in detail, only a brief description of some promise API and trial scope:
Create a native promise with the Fs.readdir function of Nodejsvar pr
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