mdx basics

Java BASICS (1)-data types and java Basics Java has two data types: Basic data types and basic data types can be directly allocated to the stack. Reference data type. The reference is stored in the stack, and the object is stored in the heap. There are eight basic data types: Class 1: char) Type 2: logical (boolean) Category 3: INTEGER (byte, short, int, long) Category 4: float (float, double)

Java basics-Bubble sorting, java basics bubble // Bubble sort, and compare public static void sort1 (int [] aa) {int size = aa from the back of the array. length; int temp; // cyclic array for (int I = 0; I Sort idea: the first layer for loop, each value in the loop array, the second layer for loop, compare the size of aa [I] In the first for loop with other numbers starting from I + 1. If it is smaller

Java basics-New I/O technology (NIO) and basics nioBefore JDK1.4, I/O input/output processing is called the old I/O processing. Beginning with JDK1.4, java provides a series of improved new input/output features, these functions are called new I/O (new I/O) and many NEW classes are added for processing input/output.Java. nio package and sub-PackageIn addition, many classes in the original java. io package a

Java basics --- Servlet listener, basics --- servlet Before writing this article, read the school friends write, I feel the basic knowledge of induction is very comprehensive, I am not cumbersome to write here, link address (http://www.cnblogs.com/sherryueda/p/4273169.html ), I will write down the specific application of the listener: The function is used to listen to various WEB operations. When an event i

Linux BASICS (1), linux BASICS (Linux Command:/root directory. current directory .. files starting with "·" in the upper-level directory are hidden files, and files starting with "d" are folder man + query content or commands: view the help (external command) query content or command -- help: a simple view of help is not as good as man's Detailed help + built-in command name: View help (built-in command) ls

Python basics 1 and python Basics Variable: Information stored, called, modified, or operated in the future Constant: Fixed amount, all uppercase letters Naming rules: Note: #: Comment on a single line "Or ''': multi-line comment Get user input: Input ("") Strong conversion:Str (integer type) # convert Integer type to string type Int (string accepted) # convert string type to integer type Arithmetic Operato

Python basics-functions and python Basics A function is a function block that can be called repeatedly. I. Definition Def function name (parameter):... function body... return value Requirements: Def: function keyword Function Name: the name of the function used for future calls. Function body: code segment for running some operations Returned value: whether the function is successfully run or not, or

Python BASICS (1): python Basics 1. Dynamic Assignment Method Name = input ("name :")Age = int (input ("age :"))Print (type (age ))Job = input ("job :")Info = '''------ Info of % s ------Name: % sAge: % sJob: % s''' % (Name, name, age, job)Info1 = '''------ Info of {0 }------Name: {0}Age: {1}Job: {2}'''. Format (name, age, job)Info2 = '''------ Info of {_ name }------Name: {_ name}Age: {_ age}Job: {_ job}''

Python basics special symbols and python basics special symbols # \ N carriage return # \ R line break # \ S space # \ T tab, do not know? Open a txt text file and press the tab key on the computer, that is, the one on caps lock. in the slot, you can see a large space (or ultra-short space). This is the tab character. # Other functions will not be used. These functions are sufficient. # % D Number Pr

Python basics _ type_dict, python basics _ dict # The dict dictionary is not as suitable as the key-value dictionary. I don't know how this name came from. It can be used for usernames and passwords, but isn't it too low to use this database? # Expand with braces {} and separate each element with commas (,). Each element must have key and value, and key and value are separated by colons. A = {'A': 1, 'B'

01Python basics _ 09 exception, 01Python basics _ 091. try try t Original program: 1 import math2 3 while True:4 text = raw_input('> ')5 if text[0] == 'q':6 break7 x = float(text)8 y = math.log10(x)9 print "log10({0}) = {1}".format(x, y)View Code This code receives the input from the command line. When the input is a number, calculate its logarithm and output it until the input

Inner class BasicsClasses are defined inside the class, either in the member's inner class or in the local inner class (inside the method)First, members of the internal class① can have access modifiers②class File Name: External class class name $ internal class class name. class③ is a complete, independent class④ can be new in any of these non-static places, but external class objects must be used in third parties. New way of generating inner classStudent s = outside.new Student ();⑤ static inne

Python basics and python Basics Variables and assignments Name = 'kevin ': if the value of a variable is of the str type, it must be caused ''. Age = 21: ''is not required if it is an int'' Variables and names Easy to understand: it is best to be knowledgeable Nums_of_kevin_gf = 10 NumsOfKevinGf = 20: hump method Name-of-kevin-gf = 10: the non-standard naming method triggers a

Python function basics 2: python function Basics 1. What are naming keyword parameters? Format: All parameters after * are named keyword parameters. Features: 1. The caller of the constrained function must pass the value in the form of Kye = value. 2. The caller of the constraint function must use the specified Key name. def auth(*args,name,pwd): print(name,pwd)auth(pwd='213',name='egon')def register(nam

Python self-learning log-basics (1) and python Basics From Understanding python to learning python, I experienced a long time of psychological struggle. People always have a natural fear of unknown things, but they are curious about the unknown. In the end, I opened this door and started to learn python. Python is actually quite interesting. This article mainly introduces python in basic aspects. 1. install

Java basics --- Exception Handling, java basics Exception Handling Recognition exception An instruction stream that causes program interruption when an exception occurs. If the exception is not correctly handled, the program may be interrupted and cause unnecessary losses, therefore, in the program design, we must consider the occurrence of various exceptions and properly handle them so as to ensure the nor

A list of python basics and python Basics List Function The list function converts other types of sequences to a list, as shown in figure >>> List ("hello world ")['H', 'E', 'l', 'l', 'O', '', 'w', 'O', 'R', 'l ', 'D'] List operations Element assignment can change the list, as shown in figure >>> Sen['H', 'E', 'l', 'l', 'O', '', 'w', 'O', 'R', 'l ', 'D']>>> Sen [0] = 'H'>>> Sen['H', 'E', 'l', 'l', 'O'

Java basics-annotations and java Basics Annotation is a form of metadata that provides non-program data and has no direct impact on the annotated code. This article mainly summarizes the usage of comments. java platform (SE) pre-defined comments. Type comments are used with the pluggable type system for stronger type checks, and how to implement repeated comments. Annotations have many functions, including:

Java basics-generic 1 and java Basics The use of generics can make the type name as a parameter in the class or interface definition, just like a common parameter, so that the defined type is more universal. Advantages of generics: Strict type check for compilation The java compiler is more rigorous in checking the type of generic code and can detect some runtime errors in common code. Eliminate type

Java basics-network programming, java basics Network Programming I. IP and InetAddress Java supports the development of network communication programs. It mainly provides two communication protocols: TCP and UDP. Reliable connection and transmission, and third-party handshake Unreliable connection transmission, which is not necessarily acceptable to the receiver during transmission All network program d