types of certifications

First, the basic data type:byte: 8 bits (BIT), which is 1 bytes, the maximum amount of data stored is 255, and the data range stored is-128~127. Default value 0Short: 16 bits, 2 bytes, value range-32768~32717, default value 0int: 32 bits, 4 bytes, value range-2147483648~2147483647, default value 0long: 64 bits, which is 8 bytes-2^63~2^63-1, default value 0Lfloat: floating point, 32 bits in memory, 4 bytes, for storing a number with a decimal point (the difference from a double is that the float

IntroductionThis article mainly introduces. NET 6 Important concepts: stacks, heaps, value types, reference types, boxing, unpacking. This article begins with a description of what happens inside the compiler when you declare a variable, and then introduces two important concepts: stack and heap, and finally introduces value types and reference

. NET Six musketeers: Stacks, heaps, value types, reference types, boxing and unpackingOne. " Heap "," stack "zoneI believe you are too familiar with these two words, even rice is what? I don't know... What is "heap" and "stack"? Oh, this one knows ...Before I also wrote a stack of articles, but not deep in writing, the analysis is not comprehensive, so today also refer to some of Daniel's information.I. Pr

1. Value type (ValueType)Value types include: numeric type, struct, bool, user-defined struct, enum, nullable type.Variables of value types store data directly and are allocated in the managed stack. Variables are automatically released when the method that created them is returned, such as declaring a char-type variable name= ' C ' in a method, and the memory that the name variable occupies on the stack is

Value type: int double char bool decimal struct enum value stored on the stack of memoryReference type: string array custom class interface delegate values are stored in the heapValue passing: The value type is passed as a parameter, passing the value itself----NOTE: Ref can change the value pass to a reference passReference passing: Passing the value of a reference type as a parameter, passing a reference static void Main (string[] args) { int number = ten; T

All types of HTML5 forms, html5 form types 1. button: defines the clickable button (usually used with JavaScript to start the script ). 2. checkbox: Define the check box. 3. cancel: cancels the submit submission. 4. color: defines the color picker. 5. date: defines the date control (including year, month, and day, excluding time ). 6. datetime: defines the date and time controls (including the year, month,

original value, the reference type data is passed the address of the Reference object1 functionAddten (num) {2num + = 10;3 returnnum;4 }5 6 varCount=20;7 varresult=Addten (count);8 9Console.log (count);// -Ten OneConsole.log (result);// - A - functionsetName (obj) { -Obj.name= ' Tom '; the } - - varMouse={name: ' Jerry '} - SetName (mouse); + -Console.log (Mouse.name);//Tom4. Comparison of type detection1) When the basic type is detected with TypeOf, the return may be string,boolean,numbe

and does not have to be entered with "FLV-application/octet-stream ". Follow these steps to add MIME type ing settings in FLV format to the server:"Start"> "Control Panel"> "Administrative Tools"> "Internet Information Service (IIS manager)", find your website, right-click "properties"> "HTTP header"> "MIME type"> "new", and enter ". in the "FLV" and "MIME type" boxes, enter "FLV-application/octet-stream" and click "OK. The "MIME type" is only a description and does not have to be entered wit

1. A reference type is a container, and a container is its own child element2. The basic type is a separate elementDifferenceContainers have their own properties (properties, methods)Basic Type NoA variable that has its own property is a reference-type variableThe inverse is the basic type.You can try the following variable to declare the root one later. "Will there be properties, methods appearing?"int i=0;String a= "0";Boolean b=true;List list=new ArrayList ();List.add ("St");Array Ae=null;byt

Introduction to packaging types in Javascript and javascript packaging types Recently, I did not read the rhino book. The translation was very bad and easy to understand, especially the prototype. Later I was introduced by my colleagues and I bought this js advanced program design, then, let's continue to look at it. Let's continue to talk about the fresh packaging type in js. I. String Speaking of the Stri

Comparison of the two types of SQL statements and comparison of the two types of SQL statementsSUM (p. payable-p. single_price) AS profitCount,M. order_id AS orderId,M. create_time,M. dept_airport_code,M. arrv_airport_code,M. payable AS priceFROMOm_passenger p,Om_order mWHEREP. order_id = m. order_idAND p. ticket_status = '1'AND m. create_type = 3AND m. order_status = '20140901'GROUPP. order_idORDERM. creat

Java operation MySQL database access images and other types of files, other types of mysql1. Notes 1. When the database field isBlobType, must usePreparedStatementInSetBinaryStream (int, InputStream, int)Method;2. When the database field isLongblobType, must usePreparedStatementInSetBinaryStream (int, InputStream, long)Method.Otherwise, an error such as the question is thrown:Exception in thread "main" java

Common security vulnerability types Security Vulnerabilities Example Weak Password § The employee uses an empty or default password Software without timely Patching § The patch is not the latest. § No security is used for timely repairProgram Improperly configured software § The Service has excessive permissions. The service runs with a local system user account. Socia

I:1: If the parameter is of the basic data type (four types and eight types: byte, short, Int, long, double, float, double,Boolean, char), then the value of the variable is passed, for example: int A = 10; then the passed value is 10! Example:Package qqwwffg. pass_method_paramater; Public class primitivetype {Public void change (int ){A = 3;}Public static void main (string [] ARGs ){Int A = 1;Primitivetype

Deep Copy Part code:C # entity class serialization and deserialization one (XmlSerializer)C # entity class serialization and deserialization two (DatacontractserializeR) Copyright: jiankunking Source: http://blog.csdn.net/jiankunking This article is copyright to the author and Csdn, Welcome to reprint, but without the consent of the author must retain this paragraph, and in the article page obvious location to the original connection. C # Object Comparisons (value

Convert string type to byte[]:byte[] ByteArray = System.Text.Encoding.Default.GetBytes (str);Byte[] turn into string:String str = System.Text.Encoding.Default.GetString (ByteArray);The string type turns to ASCII byte[]:("01" turn into byte[] = new byte[]{0x30,0x31})byte[] ByteArray = System.Text.Encoding.ASCII.GetBytes (str);Asciibyte[] turn into string:(byte[] = new byte[]{0x30, 0x31} turns into "01")String str = System.Text.Encoding.ASCII.GetString (ByteArray);Byte[] Go to 16 binary format str

[] to store data, there is an extended process when writing data, meaning that the length of the stream is not the length of its byte[] field. And GetBuffer returns is byte[] This field. Here is a partial implementation of GetBuffer, perhaps read this will be more clear: public byte[] GetBuffer () {return this._buffer;}Here's how ToArray is implemented:Public byte[] ToArray () {Byte[] bs = new Byte[this._length-this._origin];for (int i = this._origin, j = 0; i Bs[j++] = This._buffer[i];return BS

Value type Reference type Memory allocation Locations Allocation in the stack Allocating in the heap Efficiency High efficiency, no address translation required Low efficiency, requires address translation Memory Recycling When you're done, recycle it now. Not immediately recycled after use, waiting for GC to recycle Assignment operation Make a copy, create a new object of the same value Just

ImportJava.util.Scanner; Public classscannerinttest{ Public Static voidmain (String [] args) {intnum1,num2; NUM1= Getintnumber ();//Call Function Getintnumber () to get an integer entered from the keyboardnum2 =Getintnumber (); System.out.println ("First number" +num1+ "-----" + "second number" +num2);//print the two int integers you entered } Public Static intGetintnumber () {intIntnumber;//the definition returns the required int integerString strtest;//define strtest to make type judgme

2 reference typesIncludes class classes, interface interface, representing delegate, arrays arrayClass 2.1For value types, each variable directly contains all of its own data, creating a region in memory for each variable, and for reference types, each variable stores only a reference to the target data, and each variable creates a pointer to the target data. Public Static voidMain () {//structureSc