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About java : Whats-the-difference-between–cp-and–classpath

Question Detail

What’s the difference between using

javac -cp classes helloworld.java


javac -classpath classes helloworld.java

in CMD?

Question Answer

They are the same, check http://docs.oracle.com/javase/7/docs/technotes/tools/windows/java.html

-classpath classpath
-cp classpath Specifies a list of directories, JAR files, and ZIP archives to search for class files. Separate class path entries with
semicolons (;). Specifying -classpath or -cp overrides any setting of
the CLASSPATH environment variable.

If -classpath and -cp are not used and CLASSPATH is not set, then the
user class path consists of the current directory (.).

As a special convenience, a class path element that contains a base
name of * is considered equivalent to specifying a list of all the
files in the directory with the extension .jar or .JAR. A Java program
cannot tell the difference between the two invocations.

For example, if directory mydir contains a.jar and b.JAR, then the
class path element mydir/* is expanded to a A.jar:b.JAR, except that
the order of jar files is unspecified. All jar files in the specified
directory, even hidden ones, are included in the list. A class path
entry consisting simply of * expands to a list of all the jar files in
the current directory. The CLASSPATH environment variable, where
defined, will be similarly expanded. Any class path wildcard expansion
occurs before the Java VM is started. No Java program will ever see
wild cards that are not expanded except by querying the environment.
For example, by calling System.getenv(“CLASSPATH”).

There’s absolutely no difference. It just tells the Java compiler you want to use a custom classpath specified on the command line argument.

So -cp and -classpath are fully equivalent.

You can find more info on javac – Java programming language compiler page.

There is none. They’re both options for setting the classpath. See the man page.

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