201621123069 Java programming 1th Week of study summary

1. Summary of this week's study

This week, starting with a simple understanding of Java's history, to know exactly what the JDK is for developers, the JVM allows Java to run across platforms, the JRE is to provide a running environment, and how to install JDK and Eclipse on its own computer.

2. Written work

1. Virtual machines
1.1 What are the steps to execute a Java program? Why are Java programs running across platforms? (Please organize your own language answer, do not directly copy the Web reference, if there is a reference please use the > mark, otherwise-5 points)

The step is to compile the Java file into a class file before parsing the class file. Java can run across platforms because there is a JVM.

1.2 What is the JDK?JDK, JRE, and JVM connection?
The JDK is the abbreviation for Java Development Kit, which means the Java SDK, which belongs to a development environment.

The JDK includes the JRE and JVM,JRE including the JVM

Java and Javac
2.1 The Java HelloWorld command, what does this command mean? HelloWorld What does this parameter refer to?

The meaning of this command is to require the virtual machine to execute helloworld.class. This parameter refers to the file name.

What is the use of the 2.2 path variable?

Allows us to find the commands we execute through it.

2.3 What is the difference between writing a program in Java and running a program and running it with the C language, and the intermediate and target files that are generated?

In general, the suffix is different, the Java generated intermediate file is the Source.class,c source program is source.obj. C, direct compilation will get the file of the. exe, and Java requires virtual machine execution.

3.1 Read some of the routines for submitting Java programs in PTA. Answer: How to handle input in PTA? How do I format the output?

The input is scanner via import java.util.Scanner, and the output is System.out.println ().
3.2 5-2 (take the number) experiment summary.

This problem my idea is to enter an integer type, and then to judge, is negative to his absolute value, within 10000 to 20000 with the Java tostring,tooctalstring and the tohexstring function output the number of each of the binary. If in other scopes, the number is converted into a string, each output his character and a space in each middle, and finally a loop to calculate the and of each number.
3.3 5-3 (take digital floating point) experimental summary.

My idea is to directly input a number a string, and then use a loop to read each of its numbers, with sum each number together, there is a detail because the function is derived from the ASCII code, so that each number will be deducted a ' 0 '.

What are the main applications of 4.Java? What are your goals and expectations in this course?

I will C and Java, but master not fine, still need to improve, C up to write 400 lines or so of code, Java is just beginning, 40 rows or so.

I hope I can master this course, it will be helpful in the future.

3. Using the code cloud to manage Java code 3.1 git

Build your project on the Code Cloud (project name: java+ number, e.g. java201321123001). After synchronizing to this machine, build the EXP1 package, write the HelloWorld, and push it to the remote repository. Please native (local project, local warehouse), remote warehouse. Add-ons: Use command-line git to manage your code.

3.2 Question Set "Java Basic Syntax" PTA Submission List

3.3 Using the JAR program developed by the elder sister and the seniors to count the weekly code volume

Do not know how to operate ...

201621123069 Java programming 1th Week of study summary