What is the environment variables? Why do all kinds of office software, image processing software, games don't need what environment variables? Why should the IDE environment variable, where is it special?

CodePudding user response:

Environment variable is the system parameters, Windows can be set through the set command to list or in the CMD, is the main path, in order to make the software to find a Java program

Java is a public program, eclipse, such as command line software needs to be, don't know where the Java program the software, so joined the Java path in the path, you can directly use Java
Java also can install multiple versions, you are in the version specified in the environment variable is used by default version

Eclipse needs to find the Java, depend on the path environment variable,

Other software and rely on, rely on the system libraries, so the system has the default path, Windows/system32 is has some Windows system, other software during the installation process, the dependent libraries (mainly DLL) installed to the system directory, so you can run directly

CodePudding user response:

Environment variable, simply is to make the program can automatically adjust the user configuration and use of user must abide by the agreed variables,
Such as A user wants to use the program, but A user start the program need to rely on libraries on A path, users also want to use the program B, but B users start programs need to rely on libraries in B path, so that each user's machine environment differ in thousands ways all don't, how can the differ in thousands ways of tonghua so that the program can use no difference? It is introduced the environment variables, such as A user to set the classpath environment variable path (A, B users set the classpath environment variable path B, this program just read the classpath environment variable, you can find the right start rely on class library, so no matter how the user's machine environment differ in thousands ways, as long as the user comply with convention set the classpath environment variable, the program can not run, this is the origin of environment variables exist and A special place,
Office software, image processing software, because not developing software such as game, will not use additional third-party libraries installed, so there's no need to consider the user environment differences; Extra like Java development software, installation of third party software paths may be different, such as A user to json parsing bag on A path, user B in B path, that as long as the users are in additional json classpatn variable analysis package path, json parsing package can normal use, so the software development and general application software, or A little bit difference between the general application software does not need to consider the difference of user environment, everything is centralized in the software installation path, so it is not necessary to use environment variables,

CodePudding user response:

In a nutshell, after setting, your program can be executed directly,

CodePudding user response:

Java code running on the virtual machine is running, the virtual machine is running need to various environment, different system requires environment is different, so you want to configure these environment variables,