Android

Android – Intents and Filters

An Android Intent is an abstract description of an operation to be performed. It can be used with startActivity to launch an Activity, broadcastIntent to send it to any interested BroadcastReceiver components, and startService(Intent) or bindService(Intent, ServiceConnection, int) to communicate with a background Service. The […]

Android

Android – Fragments

A Fragment is a piece of an activity which enable more modular activity design. It will not be wrong if we say, a fragment is a kind of sub-activity. Following are important points about fragment − A fragment […]

Android

Android – Content Providers

A content provider component supplies data from one application to others on request. Such requests are handled by the methods of the ContentResolver class. A content provider can use different ways to store its data […]

Android

Android – Broadcast Receivers

Broadcast Receivers simply respond to broadcast messages from other applications or from the system itself. These messages are sometime called events or intents. For example, applications can also initiate broadcasts to let other applications know that […]

Android

Android – Services

A service is a component that runs in the background to perform long-running operations without needing to interact with the user and it works even if application is destroyed. A service can essentially take two states − […]

Android

Android – Activities

An activity represents a single screen with a user interface just like window or frame of Java.Android activity is the subclass of ContextThemeWrapper class. If you have worked with C, C++ or Java programming language […]

Android

Android – Hello World Example

Let us start actual programming with Android Framework. Before you start writing your first example using Android SDK, you have to make sure that you have set-up your Android development environment properly as explained in Android […]

Android

Android – Application Components

Application components are the essential building blocks of an Android application. These components are loosely coupled by the application manifest file AndroidManifest.xml that describes each component of the application and how they interact. There are following four […]

Android

Android – Architecture

Android operating system is a stack of software components which is roughly divided into five sections and four main layers as shown below in the architecture diagram. Linux kernel At the bottom of the layers […]

Android

Android – Environment Setup

  You will be glad to know that you can start your Android application development on either of the following operating systems − Microsoft Windows XP or later version. Mac OS X 10.5.8 or later […]

Android

What is Android?

  Android is an open source and Linux-based Operating System for mobile devices such as smartphones and tablet computers. Android was developed by the Open Handset Alliance, led by Google, and other companies. Android offers a unified approach […]

Android

Android Tutorial

Android is an open source and Linux-based operating system for mobile devices such as smartphones and tablet computers. Android was developed by the Open Handset Alliance, led by Google, and other companies. This tutorial will […]

Delphi

Pascal – Classes

You have seen that Pascal Objects exhibit some characteristics of object-oriented paradigm. They implement encapsulation, data hiding and inheritance, but they also have limitations. For example, Pascal Objects do not take part in polymorphism. So […]

Delphi

Pascal – Object Oriented

We can imagine our universe made of different objects like sun, earth, moon, etc. Similarly, we can imagine our car made of different objects like wheel, steering, gear, etc. Same way, there are object-oriented programming […]

Delphi

Pascal – Date and Time

Most of the softwares you write need implementing some form of date functions returning current date and time. Dates are so much part of everyday life that it becomes easy to work with them without […]

Delphi

Pascal – Units

A Pascal program can consist of modules called units. A unit might consist of some code blocks, which in turn are made up of variables and type declarations, statements, procedures, etc. There are many built-in […]

Delphi

Pascal – Memory Management

This chapter explains dynamic memory management in Pascal. Pascal programming language provides several functions for memory allocation and management. Allocating Memory Dynamically While doing programming, if you are aware about the size of an array, […]

Delphi

Pascal – File Handling

Pascal treats a file as a sequence of components, which must be of uniform type. A file’s type is determined by the type of the components. File data type is defined as − type file-name […]

Delphi

Pascal – Sets

A set is a collection of elements of same type. Pascal allows defining the set data type. The elements in a set are called its members. In mathematics, sets are represented by enclosing the members […]

Delphi

Pascal – Variants

Pascal supports a unique type of storage named variants. You can assign any simple type of values in a variant variable. The type of a value stored in a variant is only determined at runtime. […]

Delphi

Pascal – Records

Pascal arrays allow you to define type of variables that can hold several data items of the same kind but a record is another user-defined data type available in Pascal which allows you to combine […]

Delphi

Pascal – Pointers

Pointers in Pascal are easy and fun to learn. Some Pascal programming tasks are performed more easily with pointers, and other tasks, such as dynamic memory allocation, cannot be performed without using pointers. So it […]

Delphi

Pascal – Arrays

Pascal programming language provides a data structure called the array, which can store a fixed-size sequential collection of elements of the same type. An array is used to store a collection of data, but it […]

Delphi

Pascal – Booleans

Pascal provides data type Boolean that enables the programmers to define, store and manipulate logical entities, such as constants, variables, functions and expressions, etc. Boolean values are basically integer type. Boolean type variables have two […]

Delphi

Pascal – Strings

The string in Pascal is actually a sequence of characters with an optional size specification. The characters could be numeric, letters, blank, special characters or a combination of all. Extended Pascal provides numerous types of […]

Delphi

Pascal – Variable Scope

A scope in any programming is a region of the program where a defined variable can have its existence and beyond that variable cannot be accessed. There are three places, where variables can be declared […]

Delphi

Pascal – Procedures

Procedures are subprograms that, instead of returning a single value, allow to obtain a group of results. Defining a Procedure In Pascal, a procedure is defined using the procedure keyword. The general form of a procedure definition […]

Delphi

Pascal – Functions

Subprograms A subprogram is a program unit/module that performs a particular task. These subprograms are combined to form larger programs. This is basically called the ‘Modular design.’ A subprogram can be invoked by a subprogram/program, […]

Delphi

Pascal – Loops

There may be a situation, when you need to execute a block of code several number of times. In general, statements are executed sequentially: The first statement in a function is executed first, followed by […]

Delphi

Pascal – Decision Making

Decision making structures require that the programmer specify one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to […]

Delphi

Pascal – Operators

An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. Pascal allows the following types of operators − Arithmetic operators Relational operators Boolean operators Bit operators Set operators String […]

Delphi

Pascal – Constants

A constant is an entity that remains unchanged during program execution. Pascal allows only constants of the following types to be declared − Ordinal types Set types Pointer types (but the only allowed value is […]

Delphi

Pascal – Data Types

Data types of an entity indicates the meaning, constraints, possible values, operations, functions and mode of storage associated with it. Integer, real, Boolean and character types are referred as standard data types. Data types can […]

Delphi

Pascal – Basic Syntax

You have seen a basic structure of pascal program, so it will be easy to understand other basic building blocks of the pascal programming language. Variables A variable definition is put in a block beginning […]

Delphi

Pascal – Program Structures

Before we study basic building blocks of the Pascal programming language, let us look a bare minimum Pascal program structure so that we can take it as a reference in upcoming chapters. Pascal Program Structure […]