pmbok basics

First of all, I would like to thank bolow for his question raised in my blog [C ++ Basics] 028 _ getting pointers to class member functions. I have discussed with bolow and obtained the following answers. First, let's look at the following program: 1 #include 22 int (A: * fptr) () = A: Foo; give the foo address of function A as a function pointer of the Class 23 bfptr bfptr1 = (bfptr) fptr; tell the compiler to regard the above function pointer as

reading, or 1, if it returns to the end of theparameter: char[] character array while loop read, condition: If the length of the read is not -1 Combining strings FileReader fr=New filereader ("test.txt"); Char [] buf=newchar[2]; int len=0; StringBuilder SB=new StringBuilder (); while ((Len=fr.read (BUF))!=-1) { sb.append (new String (buf,0, Len)); } System.out.println (Sb.tostring ()); PHP version, file operation, write Call t

Java BASICS (3): java Basics1. Select structure and condition judgment 1. if statement An if statement contains a Boolean expression and one or more statements. If the Boolean expression is true, the code block in the if statement is executed; otherwise, the code behind the if statement block is executed. 1 import static java. lang. math. round; 2 3 public class Conditional {4/** 5 * simple if Statement 6 */7 @ Test 8 public void testIf () {9 double r

Java basics 2: java Basics1 keyword Definition: a word with special meanings given by the java language. Feature: All letters in the keyword are in lower case. Keywords used to define data types Class, interface, byte, short, int, long, float, double, char, boolean, void Keywords used to define data type values True, false, null Keywords used to define Process Control If, else, switch, case, default, while, do, f

JAVA binary basics and java binary BasicsMain Content 1. Decimal Binary Conversion 2. bitwise operation of Binary 3. JDK built-in hexadecimal conversion 4. hexadecimal in JAVADecimal Binary Conversion 57 111001 Binary bit operations: advantages: it is easy to compute and widely supported in certain situations. ① Bitwise AND (two full bits 1, the result is 1) 0 and 0 = 0; 0 and 1 = 0; 1 and 0 = 0; 1 and 1 = 1; example: 51 and 500110011-------------

Java BASICS (6): java BasicsI. Packaging JAVA is an object-oriented language. java classes connect methods with data,Basic type objects cannot be defined in JAVA,To treat basic types as objects for processing, java provides a packaging class for each basic type.. The relationship is as follows: Basic Type Packaging type Byte Byte Short Short Int Integer Long Long Float Float

Python BASICS (1): python Basics1. Variables and data types: 1.1 Variables 1. Each variable stores a value-information associated with the variable. 2. The variable can be an integer or floating point number, a string, or any data type.1.1.1 variable naming and usage Variable names can only contain letters, numbers, and underscores,And the number cannot start.Variable names cannot contain spaces, but can be separated by underscores. Python keywords an

Python basics-encoding and python Basics1. ASCII code We know that in a computer, all information is eventually represented as a binary string. Each binary bit has two states: 0 and 1. Therefore, eight binary bits can combine 256 states, which is called a byte ). That is to say, a single byte can be used to represent 256 different States. Each State corresponds to one symbol, that is, 256 symbols, from 0000000 to 11111111. In the 1960s s, the United S

JAVA basics, strings, and java BasicsString (a character array, constant, unchangeable ): 1. Create and initialize a string: 1). Use a String constant to initialize String s = "hello! "; 2). Create and initialize a String () using the constructor; // Initialize an object, indicating a NULL Character Sequence String (value); // creates a new object using an existing String constant String (char [] value); // create a String using a character array Stri

Java Basics !!!, Java BasicsQuestion 1: What are the results of 0.01 + 0.09? public class MathTest{ public static void main(String[]args){ double a = 0.01, b = 0.09; System.out.print(a+b); }} Why is the printed result 0.09999999999999999 instead of 0.1, and the loss of precision occurs? Both double and float will encounter this problem. Let's talk about float. The 0.1 binary form of float is 00111101110011001100110011001101, the exact value expressed

Python BASICS (3) and python BasicsMy life is short. I want to learn Pyhton. Python is an object-oriented, interpreted computer programming language, invented by Guido van rosum at the end of 1989, the first Public release was released on July 15, 1991. The Python source code also complies with the GPL (GNU General Public License) protocol. The Python syntax is concise and clear, and has rich and powerful class libraries. It is often called the glue

Java (Socket programming basics), socket programming BasicsI,Two main problems in Network Programming One is how to accurately locate one or more hosts on the network, and the other is how to transmit data reliably and efficiently after finding the hosts. In TCP/IP, the IP layer is mainly responsible for locating network hosts and routing data transmission. The IP address can uniquely identify a host on the Internet. The TCP layer provides an applicat

Android BASICS (16) and Android BasicsPull out a little thing Pull out a little thing Introduction Body Additional reading Target Audience: Android beginners without basic knowledge Knowledge Point: Use the support V4 package in Android Studio to implement the pull-down refresh Effect Objective: To implement the pull-down refresh function on the pageIntroduction Support V4 package Import Simple use of the SwipeRefreshLayout clas

HTML + CSS basics and htmlcss BasicsChapter 1I. Style 1. Line Style, Code cannot be maintained, not recommended 2. inline style, not reusable, not recommended 3. External style, reusable, and maintained, recommended Width of Dual-solid lineUse border-width: 4px; Set 2. Direction: border-[top | bottom | left | right] 3. Combination usage: border-top-[width | style | color] 4. border shape:Non-rectangle (inverted triangle, inverted trapezoid ......)4.1

Python BASICS (II): python BasicsVariable Another way to assign values to variables user = 'ljb'passwd = 'ljb123'user,passwd = 'ljb','ljb123' Constant Uppercase variable MYSQL_CONNECTION = '192.168.1.1' Pyc File After the import module, the pyc file is generated in the corresponding directory, and the pyc file is a bytecode file.Python call module ProcessAfter the module is called, The pyc bytecode file will be generated, and the interpreter will exe

is an executable file that runs on a 64-bit platform and uses a dynamic link file (Shared library).7. Edit the fileEditing files under Linux usually we use a dedicated command-line editor like (Emacs,vim,nano), because the content of the editor involved in Linux is more and more important, so we have a separate basic course specifically about one of these editors (VIM). here is a strong hope that you are learning this Linux basic course, you pause here first, to learn the use of the Vim editor

Overview: The composition of JavaScript, the role of each component, One, the composition of JavaScript JavascriptECMAScript (CORE) DOM (Document Object model) BOM (Browser object model) 1.1ECMAScript ECMAScript is a ECMA-262 standardized scripting language that ECMA-262 language: syntax, type, statement, keyword, reserved word, operator, object 1.2 DOM The DOM maps the entire page to a multi-tiered node structure, and each component of the page, HTML or XML, is a type of node that contain

languages such as Java, to make up for the inconvenience of not using global functions and variables in a process-oriented language, allow the declaration of static (static) and static methods in the class. In fact, the objective world does not exist the so-called static concept, because all things are objects! In the prototype object-oriented language, in addition to the built-in object (Build-in object), the existence of global objects, methods or attributes is not allowed, and there is no st

plus 1 for the array. var arr1 = []; ARR1[9] = 1; A length of 10, containing only an array of elements Setting a decimal value deletes the attribute with the property name greater than or equal to length.Setting the length value to 0 is equivalent to emptying the array. var arr2 = [1, 2, 3, 4, 5]; Arr2.length = 3; [1, 2, 3] arr2.length = 0;//[] Array traversal Traversing an array does not use a for in loop to traverse an array, because for-in will traverse all the p

Parent,intposition) {Toast.maketext ( This, "clicked" + (position + 1) + "item", Toast.length_short). Show (); } @Override Public BooleanOnlongclick (View Parent,intposition) {Toast.maketext ( This, "Long pressed the first" + (position + 1) + "item", Toast.length_short). Show (); return true; }}The rest of the layout file code does not change, rerun the program, and then you can test the click event and the long-voltage event, the effect is as follows:This is a simple way to listen to the 2 Tex