[Excellent Tutorial] Basic knowledge of Java - Getting started with java (1)

1 What are Java, Java2, and JDK? What about the 1.3 and 1.4.2 version numbers behind JDK?

Answer: Java is a universal , concurrent, strongly typed, object-oriented programming language (excerpted from the second edition of the Java Specification) JDK is a free Java development tool distributed by Sun Company, and its official name is J2SDK (Java2 Software Develop Kit).

2 What is JRE/J2RE?

Answer: J2RE is Java2 Runtime Environment, which is Java runtime environment. Sometimes referred to as JRE.

#If you just need to run a Java program or Applet, download and install it.

If you want to develop Java software by yourself, please download JDK. J2RE is included with the JDK.

Note that due to Microsoft's incomplete support for Java, please do not use IE's own virtual machine to run Applets. Be sure to install a J2RE or JDK.

3 What tool is better to use to learn Java?

Answer: The author recommends using JDK+ text editor first. This will help you understand the following basic concepts: path, classpath, package and become familiar with basic commands: javac and java. And download the API help consistent with your JDK version.

If you are not sure about the usage of a class or function, please check the API first instead of posting for help.

After you become familiar with Java, you can consider changing to another IDE. Many people recommend JCreator, but in fact the function of JCreator is still very weak.

4 What are some good reference books for learning Java?

Answer: The author first recommends Thinking in Java, the Chinese name is "Java Programming Thoughts", has a Chinese version.

The first chapter of this book introduces many object-oriented programming ideas, and novices should read it carefully.

In addition, books from O'relly Publishing House and Wrox Publishing House are also good. The author himself does not like books written by mainland authors.

#Maybe you think English is too difficult, but most of the information on the Internet is in English. In addition, you need to check the API frequently, and that is also in English.

5 Which is better, Java or C++?

Answer: This question is a very inappropriate question. You should ask: Which one, Java or C++, is more suitable for my project?

If you don’t need cross-platform or distribution, and you want to emphasize the running speed of the program, C++ More applicable. Otherwise? You should consider Java.

6 What is J2SE/J2EE/J2ME?

Answer: J2SE is just ordinary Java.

#J2ME is aimed at embedded devices, such as Java mobile phones, which has its own SDK. J2EE uses the J2SE SDK.

#The J2EE specification is more about the requirements for J2EE servers and the constraints on developers. For details, see the following "J2EE FAQ".

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