201671010135-2016-2017 <JAVA Programming Structure >

Java Basic Program Learning

What does it feel like to be in Java now? Exhaustion revealed the desire to learn solid, the first week of Java is looking forward to, but the second weekly hours up feeling very difficult. The knowledge of the learning point of vague, intermittent, despite repeated reading of the teacher to the courseware, made notes, encountered the topic or is very ignorant circle, may be because they do not adapt to such teaching methods, feel around the students learn are also good, the pressure is Alexander. This is where the digression comes in. Let's start this week's summary!!!!!!!!

1: Simple understanding of Identifiers: Identifiers in Java are similar to identifiers in C in that they consist of letters, numbers, underscores, and cannot begin with a number. But the difference is that the identifiers in Java can also be made up of dollar signs or renminbi symbols. 2: keyword cannot be used as variable name.

3: In Java, there are three comments, including the "/** start,/* end" Such comments can be used to automatically generate documents.

There are eight basic types of 4:java, there are no unsigned types in Java, and booleans and integers cannot be converted to each other.

5: Mixed-type conversions: low-byte to high-byte implicit conversions, high-byte to low-byte forced conversions. The character set in 6:java is Unicode encoded.

The main construction methods of 7:string are: ①string (): Create an empty string ②string (string value) ③string (char value[]) ④string (char[],int startindex,int numch ARS) ⑤string (Byte[],byte hibyte) ⑥string (byte[],byte hibyte,int startidnex,int numChars)

The basic operation of the 8:string class (1) Gets the substring of the string. (2) String connection. (3) Gets the length of the string you can convert a numeric value to a string by using the valueof () method defined in the string class. (4) Detecting whether a string is equal you can use the Equals method to detect whether two strings are equal. (5) string retrieval can be used with methods in the String class.

9: Command-line arguments each Java application has a main method with the string[] args parameter, which is used to receive arguments on the command line. (the args parameter starts with the third parameter of the command line)

The 10.java interrupt control flow statement does not have a goto statement, and the tag break statement provided in Java is similar to that in C, and is used to jump out of multiple nested loop statements.

The 11:biginteger class realizes the integer operation of arbitrary precision, and BigDecimal realizes the floating-point operation with arbitrary precision.

This is the third chapter I think more important points of knowledge summary, if there is deviation, I hope the teacher can point out the shortcomings

201671010135-2016-2017 <JAVA Programming Structure >