20155335 the first week of Java Program Design Study summary

18 chapters of the question

(1) Why do I need the JVM to cross-platform Java?

(2) What is the relationship between JVM and JDK and JRE?

(3) Why -0/3 result is 0, and -0.0/3.0 result is-0.0? (note the result behind 0 with a minus sign)

(4) Some Java developers use int a[] instead of int[] A to declare an array. What is the difference between the two?

(5) What are the consequences of defining only types, not encapsulation?

(6) What is the function of the constructor for inheritance?

(7) Why interfaces are preferred rather than inherited?

(8) Will the exception handling be retrieved automatically?

(9) What are the usage of collection?

(10)

is using iterator on the linked list more efficient than looping or recursion?

(12) Are there any functions for sorting and finding in the Java built-in library?

(11) Is there a situation where you can only use loops instead of recursion? (13) Can I reread the data from standard input? (14) Are there other pitfalls to be aware of when working with arrays? (15). is using iterator on the linked list more efficient than looping or recursion? (16) Are there any implementations of stacks and queues in the Java library? The 12th chapter summarizes Java is a high-level language, but also a resource and standard specification. Java was originally named Oak and its developer version is JDK. The JVM has the ability to cross a variety of operating platforms, documentation for the bit Code document (extension. Class), which is the executable text of the JVM. Java's execution environment is the JRE, which compiles about 2 of these are provided by the JDK. The JDK itself covers the JRE. The second chapter class is used to define the ten-pass keyword, followed by the class name. The method that defines main () is that when the public static void main (string[] args) system installs more than two JDK, the path path does not have a contract order, which determines the order of the tools under which JDK is executed. When you start the JVM, when you execute Java, the CLASSPATH environment variable is read if you do not use-CP or classpath. Only the Classpathui is specified to find the class used. The original code document is to be placed at the same level as the name hierarchy defined by the package Yoweri the three-person hierarchy. The name defined by the package and the name defined by class will be the exact name of the class.

20155335 the first week of Java Program Design Study summary