Tutorial by Examples: cond

Conditional Loop

You use the condition attribute to specify the condition to use. <cfset myVar=false> <cfloop condition="myVar eq false"> <cfoutput> myVar = <b>#myVar#</b> (still in loop)<br /> </cfoutput> <cfif RandRange(1,10) eq 10> ...

coldfusion • CFLOOP How-To

More condition checking using where()

Multiple conditions can be written using where() method as given below. // Creates a new \yii\db\Query() object $query = new \yii\db\Query(); $rows = $query->select(['emp_name','emp_salary']) ->from('employee') ->where(['emp_name' => 'Kiran', 'emp_salary' => 2500...

yii2 • Working with Databases

Null-conditional Operator can be used with Extension Method

Extension Method can work on null references, but you can use ?. to null-check anyway. public class Person { public string Name {get; set;} } public static class PersonExtensions { public static int GetNameLength(this Person person) { return person == null ? -1 : pers...

C# Language • Null-conditional Operators

Preconditions

namespace CodeContractsDemo { using System; using System.Collections.Generic; using System.Diagnostics.Contracts; public class PaymentProcessor { private List<Payment> _payments = new List<Payment>(); public void Add(Payment payment) ...

C# Language • Code Contracts

Postconditions

public double GetPaymentsTotal(string name) { Contract.Ensures(Contract.Result<double>() >= 0); double total = 0.0; foreach (var payment in this._payments) { if (string.Equals(payment.Name, name)) { total += payment.Amount; } } ...

C# Language • Code Contracts

Checking end of file inside a loop condition, bad practice?

eof returns true only after reading the end of file. It does NOT indicate that the next read will be the end of stream. while (!f.eof()) { // Everything is OK f >> buffer; // What if *only* now the eof / fail bit is set? /* Use `buffer` */ } You could correctly write: ...

C++ • File I/O

Conditional validation

Sometimes you may need to validate record only under certain conditions. class User < ApplicationRecord validates :name, presence: true, if: :admin? def admin? conditional here that returns boolean value end end If you conditional is really small, you can use a Proc: class ...

Ruby on Rails • ActiveRecord Validations

NLTK installation with Conda.

To install NLTK with Continuum's anaconda / conda. If you are using Anaconda, most probably nltk would be already downloaded in the root (though you may still need to download various packages manually). Using conda: conda install nltk To upgrade nltk using conda: conda update nltk With a...

nltk • Getting started with nltk

Ternary conditional operator

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...

Julia Language • Conditionals

Uploading a Conda Package

Before starting you must have: Anaconda installed on your system Account on Binstar If you are not using Anaconda 1.6+ install the binstar command line client: $ conda install binstar $ conda update binstar If you are not using Anaconda the Binstar is also available on pypi: $ pip install bin...

Python Language • Deployment

Different types of explicit wait conditions

In explicit wait, you expect for a condition to happen. For example you want to wait until an element is clickable. Here is a demonstration of a few common problems. Please note: In all of these examples you can use any By as a locator, such as classname, xpath, link text, tag name or cssSelector ...

selenium-webdriver • Wait

Available Conditionals

The markdown help states Available conditionals are gt, gte, lt, lte, eq, and neq.  eq equal to   neq not equal to  <!-- if version [gt C++03] -...

Documentation • Versions

Multiple Conditionals

Multiple conditions can be used.  content

Documentation • Versions

$SECONDS

The number of seconds a script has been running. This can get quite large if shown in the shell: ~> $ echo $SECONDS 98834

Bash • Internal variables

Animate at a specified interval (add a new rectangle every 1 second)

This example adds a new rectangle to the canvas every 1 second (== a 1 second interval) Annotated Code: <!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload=(functio...

html5-canvas • Animation

Conditionals

Perl supports many kinds of conditional statements (statements that are based on boolean results). The most common conditional statements are if-else, unless, and ternary statements. given statements are introduced as a switch-like construct from C-derived languages and are available in versions Per...

Perl Language • Control Statements

Run Task conditionally

propreties { $isOk = $false } # By default the Build task won't run, unless there is a param $true Task Build -precondition { return $isOk } { "Build" } Task Clean { "Clean" } Task default -Depends Build

PowerShell • Introduction to Psake

Conditional execution of command lists

How to use conditional execution of command lists Any builtin command, expression, or function, as well as any external command or script can be executed conditionally using the &&(and) and ||(or) operators. For example, this will only print the current directory if the cd command was succ...

Bash • Control Structures

Find the first element matching a condition

def lst = [10, 20, 30, 40] lst.find { it > 25 } // 30. Note: it returns a single value

groovy • Collection Operators

Second Normal Form (2NF)

To normalize the database in the second form, there must not be any partial dependency of any column on primary key. Let's consider the following example: idnamedobsubject1Mark1-1-1981Physics2Jack2-2-1982Math2Jack2-2-1982Biology3John3-3-1983Math This table is considered to have a composite primar...

database-design • Normalization