learn cassandra from scratch

Learn android from scratch (Intent preliminary. 40 .) Intent is a very important part of android, which is widely used in Activity and service. 1 Public void startActivity (Intent intent) Normal Start an Activity and transmit data through Intent 2 Public void startActivityForResult (Intent intent, int requestCode) Normal Start and receive data from another Activity progr

' final ' class methodUse Final can control our classes are limited inheritance, especially in the development of some commercial software, when appropriate to add Final restrictions are necessary. Welcome to follow Dongsheng Sina Weibo@tony_Dongsheng. Learn about the latest technical articles, books, tutorials and information on the public platform of the smart Jie classroom650) this.width=650; "title=" 00.png "src=" http://s4.51cto.com/wyfs02/M00/7

{case Monday case Tuesday case Wednesday case Thursday case Friday}because weekdays enumeration Type is Public access level, so that its members are also Public level. Welcome to follow Dongsheng Sina Weibo@tony_Dongsheng. Learn about the latest technical articles, books, tutorials and information on the public platform of the smart Jie classroom650) this.width=650; "title=" 00.png "src=" http://s4.51cto.com/wyfs02/M01/7C/AF/wKiom1bWSPyBVMHtAAAs2MB

Daoerror:errortype {case NoData case Primarykeynull}NoData indicates no data condition, Primarykeynull represents the primary key of the table ( Primary Key ) is an empty case. Then we can catch the error with the following code.Do {//try accesses a data table function or method} catch Daoerror.nodata {print ("no data. ")} catchdaoerror.primarykeynull {print (" PRIMARY key is empty. ")}Welcome to follow Dongsheng Sina Weibo@tony_Dongsheng. Learn abou

(w:length,h:length) } convenienceinit () { Self.init (width:640.0,height:940.0) NBSP;NBSP;NBSP;NBSP;}NBSP;}NBSP;VARNBSP;RECTC1 =rectangle (width:320.0,height:480.0) print ("Rectangle: \ (rectc1.width) x\ ( Rectc1.height) varrectc2=rectangle (w:320.0,h:480.0) print ("Rectangle: \ (rectc2.width) x\ (rectc2.height)") varrectc3=rectangle (length:500.0) print ("Rectangle 3:\ (rectc3.width) x\ (rectc3.height)") var rectc4=rectangle () Nbsp; print ("Rectangle 4:\ (rectc4.width) x\ (rectc4.height)")

original articles, welcome reprint. Reprint Please specify: Dongsheng's blog Array ( Array ) is an ordered set of elements of the same type. The collection elements in the array are ordered and can recur. declares a Array type, you can use one of the following statements. var studentlist1:array, Array types are often initialized at the same time as they are declared. The sample code is as follows:var studentlist1:arrayArray traversalThe most common operation of an array is traversal, which is to

Reference book: learn C from scratchSummary 1. Conditional operators and conditional expressions. Conditional budget symbol is made by "? "and": "consists of three operands of the conditional operator. The first operand can say any type of expression, such as arithmetic expression , relational expression, assignment expression and logical expression, and the following two expressions are any expressions of the same type. For example, the conditional

saved? Of course not, a simple example: a 3-layer neural network, we can not save the results of the second layer, when the BP to the second layer needs its results, can be calculated by the results of the first layer, which saves a lot of memory. To remind you, this is only my personal understanding, in fact, this article paper has not been to a good read, have time to take notes again. But the general meaning is almost like this.　　Second, how? 　　How do you do it? Share my trick, I will genera

returninflater.inflate (R.layout.fragment_dialog,container); }}Fragment_dialog.xmlXML version= "1.0" encoding= "Utf-8"?>Relativelayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content" > TextViewAndroid:id= "@+id/id_label_your_name"Android:layout_width= "Wrap_content"Android:layout_height= "32DP"android:gravity= "Center_vertical"Android:text= "Your Name:" /> EditTextAndroid:id= "@+id/id_txt_your_name"

);//Notification Management Service sends notifications you build you'll get a notification at this pointNote the inside of the Builder.setautocancel (true); If you do not want the program to automatically help you click and close, but your own code in another location to close, then you can not write this code, you can set to False, and then close the code can write // access to services Notificationmanager nm = (Notificationmanager) Getsystemservice (notification_service);

position of the image borderBorder-image-slice: Numerical value;Note: The default middle section is not displayed, and if necessary, add fillEg:border-image-slice:27 fill; (Set values, specifically pixels)3. Set tile properties for image bordersBorder-image-repeat:stretch|repeat|round;Stretch default value, image is stretchedRepeat picture tiled, truncated when hit boundaryRound picture tile, touch the border will dynamically adjust the size of the picture, until the entire container is covered

-play-state)Value:Running default value, motionPaused animation Pause6. Set the playback mode of the animation (animation-timing-function)Value:EaseLinear Uniform MotionEase-inEase-outEase-in-outStep-start immediately jumps to the end of the animation or immediately jumps to the next frame with no transitions in the middleStep-end the state at the beginning of the animation until the end of the animation, jumps to the end of the animation stateSteps (N,start|end)n means the animation is done in

1. Block-level elements can contain inline elements or some block-level elements, but inline elements cannot contain block-level elements, which can contain only other inline elements:2. Block-level elements cannot be placed in 3. There are several special block-level elements that can contain only inline elements and no longer contain block-level elements, which are the following special tags:H1, H2, H3, H4, H5, H6, p, DT4. A div tag can be included in Li:Li and div tags are loaded content cont

Linux has been learning for two years, but still a small white one. Used a lot of commands, but many did not remember, the foundation is not solid, to a large extent, is not taking notes, muddle through.From today onwards, start to organize Linux notes.Linux has--help this option for every command, which is the main way we learn commands.ls command, which is typically used to view files under a file folder.LS has no parameters and displays the non-hid

. : Wq save after leaving, if: wq! is forced to save after leaving ( common ) : e! Restore the file to its original state! Zz If the file does not change, then do not store away, if the file has been changed, then the store left! : w [filename] Save edited data to another file (similar to save new file) : R [FileName] In the edited data, read the data from another file. The file "filename" will be adde

, 0x7ecf conversion to decimal is 32463,ucs-2 with two bytes to encode characters, two bytes is 16 bit binary, 2 is 16 times equal to 65536, so UCS-2 can encode up to 65,536 characters.GBK Code:GBK full Name "Chinese character Code Extension code" (GBK "GB", "expand" the first letter of Hanyu Pinyin, English name: Chinese Internal Code specification). GBK downward is compatible with GB2312 encoding, which supports the ISO 10646.1 International standard upward, which is a connecting product of th

. property = value//set, add style attribute.Note: If the attribute is "-" linked, the "-" is removed and the first letter of the following word is capitalized. 2. Inline style and CSS cascading style common wayObject. Currentstyle. Properties IE is used to get the actual style attributes.getComputedStyle (object, null). Firefox is used to get the actual style attributes.Note: You can only get settings that cannot be set.7:dom Additions and deletions changeOne: Create nodes (Notes and document n

event occurs.Event.button: Returns an integer that indicates which mouse button was clicked when the event was triggered. 0 Specify the left mouse button, 1 specifies the mouse wheel, 2 specifies the right mouse button. However, the old version of IE does not comply with the specifications of the Internet , its Button property meaning as follows: 1 left mouse button 2 right mouse button 3 at the same time press 4 wheel 5 left button plus the wheel 6 right button plus the wheel 73 simultaneously

have various problems). Solution: Encapsulate the code separately into two anonymous self-executing functions (function () {' Use strict '; var a = 4;var B = 3;console.log (A + b);}) ();(function () {var c = 6;var D = 7;console.log (c + D);}) ();5: Strict mode changes syntax and behaviorStrict mode has made some changes to JavaScript's syntax and behavior.1 : The global variable is explicitly declared. In normal mode, if a variable is assigned without a declaration, the default is the global va

Object Basics1. OOP2. Object Application3. Type of Object3.1 Local objectsECMA-262T defines local objects (native object) as "objects provided by ECMAScript implementations that are independent of the hosting environment." In simple terms, a local object is a class ( reference type ) defined by ECMA-262.They include:　　　　Object Function Array String BooleanNumber Date RegExp Error evalerrorRangeerror referenceerror syntaxerror TypeError urierror3.2 Built-in objectsECMA-262 defines the built-in ob