learn angular 4

Easily learn multithreading (4) -- how many synchronized synchronization keywords are known, and how many threads are synchronized Each object has an exclusive lock. The exclusive lock only limits the access of the thread to its synchronization method. It does not make sense to the exclusive lock for non-synchronous methods. The synchronized keyword can be used as a modifier of the function or as a stateme

([] INT) returns a pointer to the newly allocated, zero-placed slice struct, that is, the pointer to the nil-valued slice. VaR p * [] Int = new ([] INT) // allocates slice structure; * P = nil; rarely useful VaR V [] Int = make ([] int, 100) // The Slice V now refers to a new array of 100 ints // Unnecessarily complex VaR p * [] Int = new ([] INT) * P = make ([] int, 100,100) // Idiomatic: a habit V: = make ([] int, 100) Remember that make is only used for map, slice, and channel,

Suppose you are not careful about git reset -- hard head ^ Then this commit is not in another git repository. What should I do? Is this change lost? Of course not. Git retains the reference log for every history. For example: $ Git commit-a-m "hongchangfirst commit"Now you can view the history of git. You can see two commits:$ Git log* D1f3fg5 (Head, Master) hongchangfirst commitNow let's reset the status of the first submission:$ Git reset -- hard head ^This submission failed, but we still hav

writable way, we should be able to enter it again. Above we already know how to list the created containers, just like our previous installation of the Vim container id–7409de9e92f0.The ID of the container knows, now it's time to get into the container again. Before we had exited the container, we had to start it again if we wanted to enter again.sudo docker start ID/NAMESpecify id-7409de9e92f0 later, or Name-pensive_darwin.As you can see, the container state with ID 7409de9e92f0 becomes "Up 3

Create a single view appIn the View window stall a navigation controller, the default navigation controller is automatically associated with the table view, if not required, you can delete the automatically added table view, create a new view Controller can be associated with navigation controller. (Right-drag from Nav to view, select Rootview)650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M02/6D/A5/wKiom1VoIRrTVOsaAABIDe5-hKE437.jpg "style=" float: none; "title=" Nav.png "alt=" Wkiom1vo

Look directly at the case. More simple. Not explained.PHP $chengji=" -"; #先定义一个变量赋值一个数值Switch($chengji) { Case$chengji - $chengji >= -; #case的意思是案例. If the case is set up, execute the output or do not perform the echo"Excellent"; Break; Case$chengji - $chengji >= the; Echo"Medium"; Break; Case$chengji the; Echo"Garbage"; Break; default: #违约, if this is not done in these cases. Echo"Don't know! "; Break;} ?>Follow Baidu Learn Php[

In program development, if the calling method does not exist when invoking an object's internal method, the program will go wrong, and then the program exit cannot continue execution. So, when the program calls the method that does not exist inside the object, we are prompted to call the method and the parameters used do not exist, but the program can continue to execute, at this time we will use the method called when the non-existent method "__call ()".The END Follow Baidu

interface. Echo"I eating". $food."\ n"; Once you have implemented an interface, you must provide a concrete implementation of the methods defined in the interface. }23} $test=NewHuman (); $test->eat ('Apple'); ?>The output effect is as follows:I eating apple00x2 Case TwoThe inheritance of multiple interfaces can be achieved by separating them with commas after implments.Format:Implements interface 1, interface 2,....PHPInterfaceicaneat{ Publicfunction Eat ($food);}Interfacehello{ Publicfucti

What is an abstract method? The method that we define in the class without the method body is an abstract method. The so-called no method body refers to the method declaration when there is no curly braces and the contents of it, but directly at the declaration of the method name after the end of the semicolon, and in the declaration of the abstract method also add a keyword "abstract" to decorate. Catalogue ====================================1. Declaring an abstract class, abstract method (ca

Super Admin RootRoot is just a name, and the real super User is the UID value. Each user has a unique UID value. Root has a UID value of 0Uid1-999 is a different user running the system service and cannot log on to the system by default. After the UID1000 is the individual ordinary user User name and UID storage file in/etc/passwd, password in/etc/shadow GID is a group, each user has a basic group, and the added group is an extension group. GID in/etc/group Permissions and attribution of f

Executorservice creating a thread pool, the pool can define the number of threadsA future is a result that a thread needs to return after execution, and the result can be defined by itselfCallable equivalent to Runnablepackage Com.condition;import Java.util.random;import Java.util.concurrent.callable;import Java.util.concurrent.completionservice;import Java.util.concurrent.executionexception;import Java.util.concurrent.executorcompletionservice;import Java.util.concurrent.executorservice;import

/** receives a number of integers entered by the user, ending with a 1 flag input,* Find out the maximum, minimum and average values**/Import java.util.*;p ublic class firstprogram{public static void Main (String args[]) {int X;int max = -2147483648;int min = 2147483647;int n = 0;int sum = 0; Scanner in = new Scanner (system.in); System.out.print ("Input integer:"); x = In.nextint (); while (x! =-1) {sum + = x;n++;if (x > Max) max = x;if (x Those years, lear