There are more than 600 software development programming languages, each with its own characteristics and application areas. At present, in China, the hottest programming languages ​​are nothing more than Java, C, C++, and php and .net are two kinds of network technologies, which are relatively simple. Both Java and C are object-oriented languages, which are the closest. Therefore, many people are often confused when they choose these two programming languages. Which one to learn? Which one has an advantage?
Let's first talk about Java. Java is the descendant of c language. It is based on the c language and discards some pointers and the like. Unlike c, Java is an object-oriented language. Java is a cross-platform. Java is safe. Many companies that require security have a high demand for Java. Java has also ranked first in the language list. The above is her advantage, its shortcoming is that it is not simple enough, the operating efficiency is not very high, she is not the underlying language, can not directly operate the hardware, can not operate the hardware, it is not too low-level, some things she can not do very well Such as hardware programming, embedded and the like.
Then let's talk about c, c is born earlier, in simple terms, C language is more like the basis of computer programming language, I feel that all programming languages ​​can find shadows in it more or less, so learn c language Her language transfer is also very simple, c language is a completely low-level language, such as drivers, communication protocols, etc., is also indispensable in Unix and Linux environments, and also has a lot of work in the embedded field, and c language efficiency high. The c language also has some problems, because she is process-oriented, so she is not as flexible as language-oriented Java, especially when the team is developing, she is not cross-platform and non-portable. Because it is too low-level, it has a high dependence on hardware, which causes some problems when the hardware environment changes, and the input and output of c language is relatively complicated.
Java is easier to work than C
C is actually more difficult to learn than Java. It is reasonable to say that C masters are “admiredâ€; however, because most commercial projects in the society do not necessarily require more advanced technology, they need simple implementation techniques. The simpler, the lower the cost of enterprise development, coupled with the cross-platform nature of Java, and with the development of Java in the mobile field in recent years, the demand for talents in the Java market is growing. Therefore, Java employment wages Be significantly higher.
C language is the basic language, JAVA is an object-oriented language. Before learning JAVA language, I think it is better to learn C language first, because the syntax of C language is relatively simple, but his highlight pointer is very easy to make mistakes. It's hard to use pointers well. Of course, if you use them well, it will be very helpful for your program. Otherwise, it will crash your program. JAVA is more practical for developing things, more practical, because JAVA is object-oriented. It is very similar to our thinking, so it is simpler to develop, and the C language is process-oriented, and it is different from our way of thinking, and development is rare. And it's hard. But because C can directly manipulate hardware, C is the most widely used language in some embedded systems.
In grammar
JAVA is developed from C++, so Java and C language syntax is similar.
In the grammar library
C language has its own standard library, but JAVA has its own class library.
In memory management
When the C language uses a piece of memory, it must manually release the memory. If it is not released, it will run for a long time, and the program will easily crash. Because of the need to explicitly return memory, when a function needs to return a block of memory to the caller, the problem is more complicated. So we should pay attention to: (1) allocate memory first in the caller, pass it as a parameter to the called function (2) allocate in the called function, release it in the caller after use (3 The static variable can be used in the called function to return the variable.
JAVA basically does not need to consider the memory problem. If you want to use an object, you can use new one. The back of this process is the certain memory that JRE classifies for the object. When JRE finds that you no longer use this object, it will automatically Recycling memory, that is to say, you only have to borrow things, don't have to return them, because when someone is your follow-up, you will return the things when you are not using them, but this process is still there, just JRE.
Basic types used in grammar
The C language has many basic types such as (boolean, char, byte, short, int, long, float, double, struct, union, enum) as well as arrays, pointers, and so on.
In JAVA: only 8 basic types (boolean, char, byte, short, int, long, float, double) and references.
In inheritance
Both languages ​​support method overloading
C language is multi-line inheritance, for example: cars and trucks inherit the car category, Audi 2000 inherits the car, Dongfeng truck is the inheritance of the truck, so the Audi 2000 can also inherit the truck, Dongfeng truck can also inherit the car .
JAVA is a single inheritance. For example, cars and trucks inherit the car category. Audi 2000 inherits the car. Dongfeng trucks inherit the trucks, so the Audi 2000 can not inherit the truck. Of course, the Dongfeng truck cannot inherit the car. .
Dynamic, static binding
In C, in order to allow the runtime to dynamically determine which function is called, a function must be modified with virtual. The virtual keyword is automatically inherited to support polymorphism; any member function (including static) that is not modified with virtual is statically bound, that is, which version is called at compile time.
In Java, except static, final, and private are static bindings, all methods are treated as dynamic bindings.
Initial value
In C language, it can be used without initialization.
In JAVA, it is necessary to initialize the value.
Abstract method or abstract class
The equivalent grammar of C language is "pure virtual function" and "abstract class"
Java uses the abstract keyword to decorate abstract methods or abstract classes. Final classes cannot be inherited.
Both use abstract classes as base classes in the inheritance hierarchy, provide general concepts, implement abstract methods by subclasses, and abstract classes cannot be instantiated directly into objects.
Super
The JAVA super keyword, which refers to the parent class object, is usually used to call the constructor or general method of the parent class.
C language does not have super keyword
This
Both, are only current objects
Package
C language does not
Java has the concept of a package, which can organize classes, facilitate packaging and deployment, and also facilitate class security.
There are still many differences in the grammar, so I will not list them one by one. It can be seen that JAVA is much more streamlined than C language, and it is very practical in life. C language is more powerful in operating memory. That is to say, JAVA is more suitable for working in the upper layer, as long as we know the interface is good, and the C language is working in the lower layer of the network, we must understand the agreement. In short, each has its own advantages, each with its own fields.
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