Java asks _03 Basic grammar (015) _system.exit (0) What's the use of

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1, system.exit (0) What is the use of

Looking at the source code of Java.lang.System, we can find the System.exit (status) method, the source code is as follows:

 Public Final  class System {/** * Terminates the currently running Java Virtual machine. The * argument serves as a status code;    By convention, a nonzero status * code indicates abnormal termination. * <p> * This method calls the <code>exit</code> method in class * <code>Runtime</code> .    This method never returns normally. * <p> * The call <code>system.exit (n) </code> are effectively equivalent to * the call: * <blo Ckquote><pre> * Runtime.getruntime (). exit (N) * </pre></blockquote> * * @param  status exit status. * @throws  SecurityException * If a security manager exists and its <cod    E>checkexit</code> * Method doesn ' t allow to exit with the specified status. * @see  java.lang.runtime#exit (int) */     Public Static void Exit(intStatus) {Runtime.getruntime (). exit (status); }}

It is clear from the comments that this method is used to end the currently running Java Virtual machine. Parameter status as the status code, according to the Convention, a non-0 status code represents an exception, so the status if nonzero, then the indication is an abnormal exit. Calling System.exit (n) is actually equivalent to calling:

Runtime.getRuntime().exit(n);

For System.exit (0), the following points need to be noted:

1. System.exit (0) stops the entire virtual machine, which means that even the memory is freed. and Dispose () just closes the window, but does not stop the entire application.

2. System.exit (0) is a normal exit program, while System.exit (1) or status 0 indicates an abnormal exit procedure.

3. The program exits regardless of the status value.

Java FAQ _03 Basic Syntax (015) _system.exit (0) What's the use