Tutorial by Examples: er

Proper indentation gives not only the aesthetic look but also increases the readability of the code. For example, consider the following code: %no need to understand the code, just give it a look n = 2; bf = false; while n>1 for ii = 1:n for jj = 1:n if ii+jj>30 bf = true; break end...

Assertions are used not to perform testing of input parameters, but to verify that program flow is corect -- i.e., that you can make certain assumptions about your code at a certain point in time. In other words: a test done with Debug.Assert should always assume that the value tested is true. Debu...

var pattern = createPattern(imageObject,repeat) Creates a reusable pattern (object). The object can be assigned to any strokeStyle and/or fillStyle. Then stroke() or fill() will paint the Path with the pattern of the object. Arguments: imageObject is an image that will be used as a patter...

You can also perform this task recursively, but I have chosen in this example to use an iterative approach. This task is useful if you are inserting all of your nodes at the beginning of a linked list. Here is an example: #include <stdio.h> #include <stdlib.h> #define NUM_ITEMS 10...

In Julia, a for loop can contain a comma (,) to specify iterating over multiple dimensions. This acts similarly to nesting a loop within another, but can be more compact. For instance, the below function generates elements of the Cartesian product of two iterables: function cartesian(xs, ys) f...

pushunique!(A, x) = x in A ? A : push!(A, x) The ternary conditional operator is a less wordy if...else expression. The syntax specifically is: [condition] ? [execute if true] : [execute if false] In this example, we add x to the collection A only if x is not already in A. Otherwise, we jus...

For branching The short-circuiting conditional operators && and || can be used as lightweight replacements for the following constructs: x && y is equivalent to x ? y : x x || y is equivalent to x ? x : y One use for short-circuit operators is as a more concise way to test a ...

Merge two partitions into single one ALTER TABLE table_name MERGE PARTITIONS first_partition, second_partition INTO PARTITION splitted_partition TABLESPACE new_tablespace

Overview Create a queue that we can send a message to. Oracle will notify our stored procedure that a message has been enqueued and should be worked. We'll also add some subprograms we can use in an emergency to stop messages from being deqeued, allow dequeuing again, and run a simple batch job t...

If you want to change an attribute of a control such as a textbox or label from another thread than the GUI thread that created the control, you will have to invoke it or else you might get an error message stating: "Cross-thread operation not valid: Control 'control_name' accessed from a th...

Structured Query Language (SQL) is a special-purpose programming language designed for managing data held in a Relational Database Management System (RDBMS). SQL-like languages can also be used in Relational Data Stream Management Systems (RDSMS), or in "not-only SQL" (NoSQL) databases. ...

There are three basic rules of semicolon insertion: When, as the program is parsed from left to right, a token (called the offending token) is encountered that is not allowed by any production of the grammar, then a semicolon is automatically inserted before the offending token if one or more o...

empty statement var statement expression statement do-while statement continue statement break statement return statement throw statement Examples: When the end of the input stream of tokens is encountered and the parser is unable to parse the input token stream as a single complete Pro...

// 1. Instantiate an AlertDialog.Builder with its constructor // the parameter this is the context (usually your activity) AlertDialog.Builder builder = new AlertDialog.Builder(this); // 2. Chain together various setter methods to set the dialog characteristics builder.SetMessage(Resource.Str...

If you only need a given resource for a specific control, you can make it more local by adding it to this specific control, instead of the window. It works exactly the same way, the only difference being that you can now only access from inside the scope of the control where you put it: <StackPa...

Polymorphism is one of the pillar of OOP. Poly derives from a Greek term which means 'multiple forms'. Below is an example which exhibits Polymorphism. The class Vehicle takes multiple forms as a base class. The Derived classes Ducati and Lamborghini inherits from Vehicle and overrides the base cl...

in this way '0' representing the known values ​​are ranked first, '1' representing the NULL values ​​are sorted by the last: SELECT ID ,REGION ,CITY ,DEPARTMENT ,EMPLOYEES_NUMBER FROM DEPT ORDER BY CASE WHEN REGION IS NULL THEN 1 ELSE 0 END, REGION ...

If you need to send events from fragment to activity, one of the possible solutions is to define callback interface and require that the host activity implement it. Example Send callback to an activity, when fragment's button clicked First of all, define callback interface: public interface Samp...

Every time a program opens a resource, such as a file or network connection, it is important to free the resource once you are done using it. Similar caution should be taken if any exception were to be thrown during operations on such resources. One could argue that the FileInputStream has a finaliz...

pip is your friend when you need to install any package from the plethora of choices available at the python package index (PyPI). pip is already installed if you're using Python 2 >= 2.7.9 or Python 3 >= 3.4 downloaded from python.org. For computers running Linux or another *nix with a native...