Tutorial by Examples: ch

Fetching Query Results

There are 3 main ways to fetch results from a query: sqlsrv_fetch_array() sqlsrv_fetch_array() retrieves the next row as an array. $stmt = sqlsrv_query($conn, $query); while($row = sqlsrv_fetch_array($stmt)) { echo $row[0]; $var = $row["name"]; //... } sqlsrv_fetch...

PHP • Using SQLSRV

CharField

The CharField is used for storing defined lengths of text. In the example below up to 128 characters of text can be stored in the field. Entering a string longer than this will result in a validation error being raised. from django.db import models class MyModel(models.Model): name = models...

Django • Model Field Reference

Binary Search

Introduction Binary Search is a Divide and Conquer search algorithm. It uses O(log n) time to find the location of an element in a search space where n is the size of the search space. Binary Search works by halving the search space at each iteration after comparing the target value to the middle ...

algorithm • Searching

Converting Unicode characters to “\uxxxx” format using PHP

You can use the following code for going back and forward. if (!function_exists('codepoint_encode')) { function codepoint_encode($str) { return substr(json_encode($str), 1, -1); } } if (!function_exists('codepoint_decode')) { function codepoint_decode($str) { re...

PHP • Unicode Support in PHP

Converting Unicode characters to their numeric value and/or HTML entities using PHP

You can use the following code for going back and forward. if (!function_exists('mb_internal_encoding')) { function mb_internal_encoding($encoding = NULL) { return ($from_encoding === NULL) ? iconv_get_encoding() : iconv_set_encoding($encoding); } } if (!function_exists('mb_c...

PHP • Unicode Support in PHP

Configuration types and qualifier names for each folder under the "res" directory

Each resource directory under the res folder (listed in the example above) can have different variations of the contained resources in similarly named directory suffixed with different qualifier-values for each configuration-type. Example of variations of `` directory with different qualifier value...

Android • Localization with resources in Android

match? - Boolean Result

Returns true or false, which indicates whether the regexp is matched or not without updating $~ and other related variables. If the second parameter is present, it specifies the position in the string to begin the search. /R.../.match?("Ruby") #=> true /R.../.match?("Ruby&quot...

Ruby Language • Regular Expressions and Regex Based Operations

synchronized

Synchronized modifier is used to control the access of a particular method or a block by multiple threads. Only one thread can enter into a method or a block which is declared as synchronized. synchronized keyword works on intrinsic lock of an object, in case of a synchronized method current objects...

Java Language • Non-Access Modifiers

Cut (remove choice points)

Sometimes it is desirable to prevent Prolog from backtracking into alternative solutions. The basic tool available to the programmer to stop prolog from continuing futher in its backtrack is the cut operator. consider the following. % (percent signs mean comments) % a is the parent of b, c, and d....

Prolog Language • Control structures

Check matching fields in two files

Given these two CSV files: $ cat file1 1,line1 2,line2 3,line3 4,line4 $ cat file2 1,line3 2,line4 3,line5 4,line6 To print those lines in file2 whose second column occurs also in the first file we can say: $ awk -F, 'FNR==NR {lines[$2]; next} $2 in lines' file1 file2 1,line3 2,line4...

awk • Two-file processing

Checking the syntax of a script with "-n"

The -n flag enables you to check the syntax of a script without having to execute it: ~> $ bash -n testscript.sh testscript.sh: line 128: unexpected EOF while looking for matching `"' testscript.sh: line 130: syntax error: unexpected end of file

Bash • Debugging

Newline character is not consumed in typical scanf() call

When this program #include <stdio.h> #include <string.h> int main(void) { int num = 0; char str[128], *lf; scanf("%d", &num); fgets(str, sizeof(str), stdin); if ((lf = strchr(str, '\n')) != NULL) *lf = '\0'; printf("%d \"%s\&...

C Language • Common pitfalls

Minimal Chart Example

Depending on the version of Chart.JS you are using (the current one being 2.X), the syntax is different to create a minimal example of a bar chart (JSFiddle Demo for 2.X). Chart.js 2.X <html> <body> <canvas id="myChart" width="400" height="400&...

chart.js • Getting started with chart.js

Espresso custom matchers

Espresso by default has many matchers that help you find views that you need to do some checks or interactions with them. Most important ones can be found in the following cheat sheet: https://google.github.io/android-testing-support-library/docs/espresso/cheatsheet/ Some examples of matchers are...

Android • Testing UI with Espresso

Assigning signals to a channel

Often times you will have reason to catch when your program is being told to stop by the OS and take some actions to preserve the state, or clean up your application. To accomplish this you can use the os/signal package from the standard library. Below is a simple example of assigning all signals fr...

Go • OS Signals

R in Latex with Knitr and Inline Code Chunks

Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is inline code chunks. This apporach is demonstrated below. # r-noweb-file.Rnw \documentclass{article} \begin{document} This is an Rnw file (R noweb). It contains a combination of LateX and ...

R Language • R in LaTeX with knitr

R in LaTex with Knitr and Internal Code Chunks

Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is internal code chunks. This apporach is demonstrated below. # r-noweb-file.Rnw \documentclass{article} \begin{document} This is an Rnw file (R noweb). It contains a combination of LateX a...

R Language • R in LaTeX with knitr

Creating a search form

To create a search form, enter the following code <%= form_tag("/search", method: "get") do %> <%= label_tag(:q, "Search for:") %> <%= text_field_tag(:q) %> <%= submit_tag("Search") %> <% end %> form_tag: This is t...

Ruby on Rails • Form Helpers

Create unconnected socket, try connect to it and check if connection is established

public class ConnectSocketExample { private int HTTP_PORT = 80; /** * example method to create unconnected socket * then connect to it * at end return connected socket * * @param httpHostName - endpoint host name fot socket connection * @throws IOEx...

sockets • Getting started with sockets

Chaining assignments in var declarations.

Chaining assignments as part of a var declaration will create global variables unintentionally. For example: (function foo() { var a = b = 0; })() console.log('a: ' + a); console.log('b: ' + b); Will result in: Uncaught ReferenceError: a is not defined 'b: 0' In the above examp...

JavaScript • Anti-patterns