Java Language Learning Note 1

Recently also in the Spring Festival holiday, there will always be a variety of things appear, there is no complete time to learn Java and other aspects of knowledge.

Since yesterday, with a complete learning system, I went to Lou teacher recommended Geek College website began to learn the Java language syntax. At the beginning of the holiday at the Geek College registered workers just as a task to complete, but did not find the real role of the Geek College and great value, borrow Lou Teacher blog on the words is, "through the network of learning, not only is the communication between teachers and students, but also the society, teachers and students three exchanges, So that the students ' knowledge sources will be richer and wider, the knowledge will be improved "", for this geek college, I read the relevant C language video, but also solved a part of the knowledge point of vulnerability. So I believe that Lou teacher to us know the online learning course will have a great help in Java course learning.

Today first in the Geek College first chapter development environment to build the study.

1, the first section of the introduction of Java language, from the Java language History, development environment changes, syntax changes, Java three systems (J2SE, EE, J2ME), and so on some understanding. A well-written Java program does not run directly in a computer program but runs in a Java virtual machine. The JVM (Java Virtual machine) is part of the Java Runtime environment.

2, the second section to learn the Java language development environment of the building, although the computer before learning video has been built successfully, but only mechanically steps to complete, watching the video for the overall development of software eclipse has been understood. Eclipse comes with a standard set of plugins, including Java development tools (Java Development kit,jdk).

3, the third section learned the Java Development debugging techniques and the use of Eclipse shortcut keys. In this section I learned two small points of knowledge. The first one is about the output function,

Output function system. Out. println (""), and the contents of the parentheses inside what type can be, such as numbers, letters, string type can be successfully manipulated. This output function appears in the development environment simply by entering SYSO.

Output function System. Err. println (""), which is different from the above output function for this output function in the debug results shown in the red font, the above function output is black, if it is necessary to use this function during the compilation of the function, but the second function is generally used to display the error results.

The second function is to build the environment's own default function E. Printstacktrace (); This function is used for the error tracking list, and the return value has a relatively close meaning.

There is also a hexadecimal number in the Java code in 0x (0 instead of the English letter O).

Java Language Learning Note 1