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Scope is for variables, for example, we create a function that contains a function, and now there are three scopesGlobal scope ==> function 1 Scope ==> function 2 scopeThe scope is characterized by first finding it in its own variable range, and if not, it will look up along the scope.Such as:var a = 1;function B () { var a = 2; Function C () { var a = 3; Console.log (a); } C ();}

Note: This article comes from " what is Ooa in Java?" What is Ood? What is OOP? "In Java, what is OOA?

. Second, by abandoning individual things in the details of the differences, extracting their common characteristics and get a group of things abstract concept.Abstraction is the most widely used principle in object-oriented methods. Abstract principles include two aspects of process abstraction and data abstraction.Process abstraction means that any sequence of operations that completes a deterministic function can be viewed by the user as a single e

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Chapter No. 0 Introduction Bitcoin is a set of software, the software code to modify the upgrade will often involve two concepts, a called hard fork, a soft fork. What the hell does that mean? The most common definition in the community is the modification of consensus. But it is difficult to understand

What is cocoa? What is Xcode? What is the framework? What is cocoa?Many libraries (libraries) and tools built into the NeXTSTEP (operating s

Everything is different from the first to the fourth year. From the first to the fourth day, there is no such thing as a basket. The food is not so sweet, and the sleep is not so comfortable. How many people have troubles with work and nonsense.Http://bbs.sei.ynu.edu.cn/viewthread.php? Tid = 27480 extra = Page % 3d8 M

What is a scripting language? What is a compilation language? What is the difference between the two ?, Script language compilation What is

verification code is a bad user experience, not necessary to not easily use the verification code, many of the current practice is that if a short period of time to submit a form is not successful after the request to provide a verification code, This will get a better user experience. Add: Firewall is an imp

What is a construction method?The construction method is called when the new object is created. Each class has a constructor method, and if the programmer does not provide a constructor for the class, the Java compiler creates a default constructor for the class.What is a co

This problem has actually plagued me for a long time. I have asked many people what is "null? What's the purpose? Most people answer: "null is a special 0 defined by the system. Pointing your initialized pointer to it can prevent the evil effects of" wild pointer. " Today, I met a C-language pen question, which is

previous versions of FF, the plug-in vulnerability has been fixed, so FF cannot complete the dark Data Warehouse through memory. Because the file operation FF does not provide support (data transmission cannot be completed through cookie cross-origin), this technical method can only be used in IE. 5. In combination with the preceding methods, when accessing website a, request website B to complete data processing and obtain the desired results based on the returned ID. The disadvantage of this

, depending on the situation. The running of a thread requires the use of the computer's memory resources and CPU. The concept of multithreading Multithreading refers to the technique of implementing concurrent execution of multiple threads from software or hardware. Multithreading is to accomplish many tasks synchronously, not to improve the efficiency of the operation, but to improve the efficiency of the use of res

progress, changes, issues to be resolved, and potential difficulties, and adjust the development process in a timely manner according to the actual situation. Why is it called "extreme" (Limit) "Extreme" (Limit) means that, compared with the traditional project development method, XP emphasizes that every method and idea listed in it is the ultimate and the best. What