adobe computer programs

conditional expression:Each p (condition) is evaluated in turn, and the value corresponding to the first condition that is not false is evaluated with its value as the entire cond expression.(cond ( 1>) ; (…( )Expressions such as PN (to find a true or false value) are called predicates.It can be written in scheme: (define (abs x) (cond (> x 0 ) x) ( (= x 0 ) 0 ) x 0 ) (- x) ) ) ) In addition to predicates such as >=(And ...) Evaluates e one at a-until an e is calculated,

At plans to run commands and Program . The at command can only be used when the "scheduler" service is running. If you use it without parameters, at lists the scheduled commands. SyntaxAt [\ computername] [{[ID] [/delete] |/Delete [/Yes]}] At [[\ computername] hours: minutes [/interactive] [{/every: Date [,...] |/next: Date [,...]}] command] Parameters\ ComputernameSpecify a remote computer. If this parameter is omitted, the at program plans c

Many friends may think that after the Win7 32-bit system is turned on, only we open the program is the start of the program, in fact, you may wish to try to open the computer's Task Manager window, in the process of this column is not to see a lot of content, actually these are currently starting in the program, that is to say, Many programs are open when we open the computer, then in many

Thinking logic of computer programs (49), thinking 49 Previously, we introduced two implementation classes HashMap and TreeMap of the Map interface. This section introduces another implementation class LinkedHashMap. It is a subclass of HashMap, but it can keep the elements sorted by insert or access, which is different from the TreeMap key sorting. It is easy to understand the order by insert. What does th

, we briefly introduce Linkedhashset, which is a subclass of HashSet, but uses linkedhashmap internally.If you need a map implementation class, and the type of the key is an enumeration type, you can use HashMap, but you should use a dedicated implementation class Enummap, why? Let's discuss it in the next section.----------------To be continued, check out the latest articles, please pay attention to the public number "old Horse Programming" (Scan the QR code below), from the introduction to adv

expression is not used. (Execution efficiency is not necessarily high compared to other algorithms, and is only used to verify that the program's processing power is enhanced through rules, and that the regular expressions and program logic are not rigorously written without deep validation due to no in-depth testing)In fact, although the program is very simple, but, in fact, is a simple rule of the prototype engine.First, he loads a lot of business processing rules, plus, minus, multiply, divi

rule of the prototype engine.First, he loads a lot of business processing rules, plus, minus, multiply, divide, interpolate, index, remainder and so on.Second, his business rules can be extended continuously.Thirdly, as long as the facts are given, finally, by the constant application of the rules, he will eventually export the result, either the correct result or the fact that it is wrong.For children who need the source code, please go to git and get the codes directly.Git address: http://git

The system has become extremely difficult recently.QQ landing on the card, NetEase cloud music into not go, cool dog card dead, iOS simulator card dead ...All kinds of perverted cards dieCheck all over the network, call customer service, clear cache, re-install the system still no solution?????Half a month, it's torture.When I was about to give up my Mac, I looked at Performance Monitor and found that the programs that were stuck were all needed for a

Thinking logic of computer programs (79), thinking 79 In the previous section, we mentioned that in asynchronous task programs, a common scenario is that the main thread submits multiple asynchronous tasks and then processes the results if a task is completed, in this scenario, Java provides a convenient method for sending and distributing packets. The Completion

Thinking logic of computer programs (30), thinking Logic The previous section introduced the String, and mentioned that if String modification operations are frequent, StringBuilder and StringBuffer classes should be used. The methods of these two classes are basically the same, and their implementation code is almost the same, the only difference is that StringBuffer is thread-safe, while StringBuilder is

The MySQL service on the local computer is stopped after it is started. Some services will be automated when they are not used by other services or programs, and other mysql services Re-install the MySQL database. Due to the sloppy installation, all the way to next (in fact, strict configuration is required in some places and I forgot to pay attention to it), it is a lot of trouble now. Error message: Th

We often encounter open application prompts "Do you want to allow the following programs to make changes to this computer?" "If we do not like this much, then how to close the tip of the tube, specifically as follows." 1. Right-click the Start menu, as follows.2. Click on the "Control Panel" option to enter the Control Panel management.3. Click on the "User account and Home security" option, as shown below

Thinking logic of computer programs (59) and thinking 59 The previous two sections show you how to read and write file content through a stream. This section describes operations on file metadata and directories. File and directory operations are ultimately related to the operating system and file system. The implementations of different systems are different, but Java. io. the File class provides a unified

then sleeps for a while, then sets shutdown to true and finally outputs "exit main".The expected result is that all two threads exit, but actually executes, it is likely to be found that Hellothread never exits, that is, in the Hellothread execution flow, shutdown is always false, even if the main thread has changed to true.What's going on here? This is the memory visibility issue. In a computer system, in addition to memory, the data is also cached

Thinking logic of computer programs (80) and thinking 80 This section describes scheduled tasks. There are many application scenarios for scheduled tasks, such: An alarm program or task reminder. You can call a bed at a specified time or return a credit card on a specified date. The monitoring system collects system data at intervals to trigger alarms for abnormal events. Statistical System, which usual

Thinking logic of computer programs (78) and thinking 78 In the previous section, we initially discussed the task execution service in Java and package. In reality, the main implementation mechanism of the task execution service is the thread pool. In this section, we will discuss the thread pool. Basic Concepts A thread pool, as its name implies, is a thread pool. There are several threads in it. They are

Thinking logic of computer programs (74) and thinking 74 This section describes a commonly used concurrent container-ConcurrentHashMap, which is a concurrent version of HashMap. Compared with HashMap, it has the following features: Concurrency Security Directly supports atomic composite operations Supports high concurrency, fully parallel read operations, and parallel write operations to a certain exten

Thinking logic of computer programs (39) and thinking 39 In the previous section, we introduced the ArrayList. the random access efficiency of ArrayList is very high, but the insertion and deletion performance is relatively low. We mentioned that the List interface's parallel List is also implemented, its features are almost the opposite of that of ArrayList. This section describes the feature list in detai

Thinking logic of computer programs (45) and thinking 45 The previous sections introduced the basic container classes in Java. Each container class has a data structure behind it. ArrayList is a dynamic array, sorted list is a linked list, And HashMap/HashSet is a hash table, treeMap/TreeSet is a red-black tree. This section describes another data structure-heap. Introduce heap We mentioned heap before, whe

Thinking logic of computer programs (53), thinking 53 The previous sections introduced various specific container classes and abstract container classes. As we mentioned above, Java has a collection class that provides many common functions for container interfaces, these functions are provided in static mode. What functions are available? There are two possible types: For the first type, operations can be