Why Array Index Starts from Zero?

It starts at 0 because the index value tells the computer how far it needs to move away from the starting point in the array. In some programming languages, if you use an array (without giving an index number in brackets), you are really only referring to the memory address of the starting point of the array. When you reference a specific value in the array, you are telling the programming language to start at the memory address of the beginning of the array and then move up the memory address as needed. So lets say a program allocates space in the memory between address numbers 1024 and 2048 and it starts at 1024 and each item in the array is 8 bytes long. Then saying arrayName[0] is the same as telling it to look at the data stored at the memory address of (1024 + (0 * 8)), or 1024. If you...

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Operator Precedence and Associativity

Note: Operators are shown in decreasing order of precedence from top to bottom in the table. Operator Type Associativity : : binary scope resolution left to right : : unary scope resolution left to right ( ) parentheses left to right [ ] array subscript left to right . member selection via object left to right -> member selection via pointer left to right + + unary postfix increment left to right - - unary postfix decrement left to right typeid runtime type information left to right dynamic_cast <type> runtime type-checked cast left to right static_cast <type> compile-time type-checked cast left to right reinterpret_cast <type> cast for nonstandard conversions left to right const_cast <type> cast away const-ness left to right + + unary prefix increment...

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Introduction to the Standard Template Library (STL)

The C++ standard committee added the Standard Template Library (STL) to the C++ Standard Library due to the importance of the software reuse benefits. The STL defines powerful, template-based, reusable components that implement many common data structures and algorithms used to process those data structures. The STL offers proof of concept for generic programming with templates. It is very important to keep in mind that in industry, the features presented are often referred to as the Standard Template Library or STL. However, these terms are not used in the C++ standard document, because these features are simply considered to be part of the C++ Standard Library. The STL was developed by Alexander Stepanov and Meng Lee at Hewlett-Packard...

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Why Linux is Free?

Linux is freeware. Freeware is a software written by somebody and the author doesn’t forbid the free distribution and usage of the software. Linux is a computer operating system, like Microsoft Windows or Apple Mac OS. Unlike those two, however, Linux is built with a collaborative development model. The operating system and most of its software are created by volunteers and employees of companies, governments and organizations from all over the world. The operating system is free to use and everyone has the freedom to contribute to its development. This co-operative development model means that everyone can benefit. Because of this, we like to call it Free Software, or Socially Responsible Software. Closely related is the concept of Open Source Software. Together, Free and Open Source Software...

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Android & iOS App Store Summary

When it comes to major apps, the line between Android and iOS is starting to blur rapidly. Choosing a smartphone or tablet platform should be a well-considered decision because switching from iOS to Android or vice versa will require you to buy apps again in the Google Play (or Apple app) store. Android is now the world’s most commonly used smartphone platform and is used by many different phone manufacturers. iOS is only used on Apple devices, such as the iPhone. iOS and Android both use touch interfaces that have a lot in common - swiping, tapping and pinch-and-zoom. Both operating systems boot to a home screen, which is similar to a computer desktop. While an iOS home screen only contains rows of app icons, Android allows the use of widgets, which display auto-updating information such...

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Quiz -- Computers Languages, Internet and World Wide Web

The company that popularized personal computing was ____________. The computer that made personal computing legitimate in business and industry was the ____________. Computers process data under the control of sets of instructions called computer ____________. The six key logical units of the computer are the __________, __________, ___________, __________, __________ and the __________. The three types of computer languages are __________, __________ and ____________. The programs that translate high-level language programs into machine language are called ____________. C is widely known as the development language of the ____________ operating system. The ____________ language was developed by Writh for teaching structured programming. The Department of Defense...

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How to Install Android SDK? (for Linux)

This tutorial will prepare you to install and configure Android on your Ubuntu Linux system. You must have Oracle Java JDK or OpenJDK on your system before installing Android SDK. OpenJDK (aka Open Java Development Kit) is a free and open source implementation of the Java programming language. You can download Oracle Java JDK from here. Now, follow these 6 steps to install Android SDK on Linux operating system. Step 1 First, boot up Ubuntu Linux,make sure you have an implementation of the Java JDK installed on your system, whether it is OpenJDK or Oracle Java JDK, which lays the foundation for the Android SDK. You have choice between installing Open JDK or installing Oracle Java. I recommend installing Oracle Java because it is usually the most well maintained and up to date version...

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Quiz -- C++ Data Types

1. How would you declare an integer called num and initialize it to 10? A. double num = 10; B. int num = 10; C. int num == 10; D. int num 10; 2. What is the correct way to write a comment in C++ ? A. /this is comment/ B. \\this is a comment C. //this is a comment D. None of the above. 3. How would you declare a double called sum and initialize it to 15? A. double add 15; B. add double = 15; C. double add 15 D. double add = 15; 4. What do double data types hold? A. two integers B. decimals C. one integer D. whole numbers 5. What is the correct way to print integer add to the screen? A. cout<<add<<endl; B. cout<<"add"<<endl; C. cout add; D. cout>>add>>endl;   6. Which is the correct way to declare multiple integers? A. int sum; num;...

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Windows 8 Keyboard Shortcuts

Knowing at least some of the Windows 8 keyboard shortcuts helps you to make your Windows 8 experience much more enjoyable. Try to memorize these top Windows 8 keyboard shortcut keys. Press the Windows key to open the Start screen or switch to the Desktop (if open). Press the Windows key + D opens the Windows Desktop. Press the Windows key + . to pin and unpin Windows apps on the side of the screen. Press the Windows key + X to open the power user menu, which gives you access to many of the features most power users would want (e.g. Device Manager and Command Prompt). Press the Windows key + C to open the Charms. Press the Windows key + I to open the Settings, which is the same Settings found in Charms. Press and hold the Windows key + Tab to show open apps. Press the Windows...

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How to Install Android SDK? (for Windows)

The Android Developer Kit, simply named as Android SDK is what all the advance users of Android should have installed on Windows running computers. In fact this tool stands behind each developer who is working in developing and testing new apps for improving, updating or unchaining different version of the Android OS. Basically, you are dealing with some codes that will be inserted in the command prompt window and through which you will be able to interact and access the system and in built programs from your handset. Eclipse is being the language in which the codes are written. Before beginning the proper operations there should be applied some pre-requisites. The Android SDK has some basic system requirement; before going any further check them by using the link from here. Also, on...

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Quiz -- C++ Basics

1. What is the correct value to return to the operating system upon the successful completion of a program? A. -1 B. 1 C. 0 D. Programs do not return a value. 2. What is the only function all C++ programs must contain? A. start() B. system() C. main() D. program() 3. What punctuation is used to signal the beginning and end of code blocks? A. { } B. -> and <- C. BEGIN and END D. ( and ) 4. What punctuation ends most lines of C++ code? A. . B. ; C. : D. ' 5. Which of the following is a correct comment? A. */ Comments */ B. ** Comment ** C. /* Comment */ D. { Comment } 6. Which of the following is not a correct variable type? A. float B. real C. int D. double 7. Which of the following is the correct operator to compare two variables? A. := B. = C. equal D. == 8. Which...

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Introduction to Android Developing

What is Android? Android is the world's most popular operating system for mobile devices and tablets. It is an open source operating system, created by Google, and available to all kinds of developers with various expertise levels, ranging from rookie to professional. (The term 'open source' sounds pretty familiar, doesn't it? Well, open-source means software with source available for modification and bound to an open source license agreement. More about open source terminology can be found here). From a developer's perspective, Android is a Linux-based operating system for smartphones and tablets. It includes a touch screen user interface, widgets, camera, network data monitoring and all the other features that enable a cell phone...

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Why Study Computer Science?

The most important aspect of computer science is problem solving, an essential skill for life. Students study the design, development and analysis of software and hardware used to solve problems in a variety of business, scientific and social contexts. Because computers solve problems to serve people, there is a significant human side to computer science as well. Top Ten Reasons to Study Computer Science The Association of Computing Machinery is an international organization for computer scientists. The ACM has developed the following list of top ten reasons to study computer science which we quote from their web site. Computing is part of everything we do!  Expertise in computing enables...

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