One of the best ways to communicate with database is to use web services. Web services are software as a service web application components which communicate with the server securely using token authentication and produce output in xml or json format for various platforms to easily use. Android, IOS, windows apps and even websites can therefore be easily be synchronized. To update the database we use GET or POST methods. GET method in PHP has all the parameters in the URL while post method doesn’t use URL parameters and is more secure way of sending data. In this tutorial we will look at how to use GET and POST methods in android to update database and retrieve data from database using JSON parsing. We will also look at uploading images to the server and maintaining a URL record in the database along with downloading and displaying images from the URL using Volley. You can download google volley library using Download Volley link.
Volley is a networking library developed by Google for the Android SDK to work with server communications without interfering the user interface. The HTTPClient method which was used earlier was not only longer in terms of code because of inclusion of AsyncTask and parsing but was required for each instance of accessing the server. Android API level 22 and above seem to have stopped giving support to that process and libraries like Google Volley and Retrofit are rather more popular among android developer communities because they not only remove the headache of asynctask for each instance but also manage caching of data and work with multiple tasks at one without issues. Parsing json is far more easier now than ever before with volley and retrofit. However, in this tutorial we will only look at Volley’s methods because its updates are supported by Google.
Continue reading Google Volley guide to working with web services using PHP, MySQL and Android Studio Tutorial
What is data structure?
A data structure is structured organization of data items. While Abstract Data Type defines what is to be done, data structures define how it will be implemented. Example: Trees, Graphs and Linked Lists.
What are the basic operations that a data structures should do?
A data structure can insert, delete and find data elements basically. Other operations include merge, find predecessor, find successor, modify/update, find min/max, delete minimum/maximum etc..
What is a data type?
Data type defines collection of objects and the set of operations that can act on them.
What are the different types of data types?
1. Primitive : int(short, long), boolean, char, float(double), string i.e. array of char (Operations on these data types are well defined by the language like arithmetic, logical operations, increment, decrement etc.. )
2. Non primitive (ADTs): Linear – Arrays, Stacks, Queues, Linked lists and Non Linear – Trees, Graphs (What operations can be performed is defined but not how!)
What are commonly used values of Big O notations?
1. O(1) means a constant computing time
2. O(n) means linear computing time
3. O(n2) is quadratic
4. O(n3) is cubic
5. O(2n) js exponential computing time
6. O(log n) is called logarithmic
7. O(n log n) is better than O(n2) but not better than O(n) eg: find an element takes O(log n) time in a binary search.
Continue reading A Quick Summary of Data Structures Concepts
If you did not know there are a lot of apps that pay you, sometimes for doing tasks, watching ads and sometimes doing nothing at all. I have been trying to find out the best apps for you so you can earn the maximum amount spending the least amount of time and yet still making nice bucks. All you will need is a mobile phone and an internet connection.
Here are some of the ways you can make money with apps :
- Installing apps : Though its a bad start to talk about the most obvious way of making money with apps, installing apps can be one of simplest methods that a lot of people use to make some bucks online. You can make around 5 to 30 usd per day (depending upon your location and ad credits) with these apps. Apps like “FeaturePoints”, “AppDown”, “TokenWall” and “TapBooty” are some of the examples of such apps.
- Completing Surveys : Reading emails, signing up to apps/websites and completing opinion tasks though most difficult can be highly rewarding. InboxDollars, i-Say Mobile, Swagbucks, Gigwalk are some of the apps which you can use to earn cash completing such surveys. There is no fixed amount that you can earn through these but they do have high potential and usually pay more than other methods.
- Lockscreen : Did you know that there are apps that pay you just for setting their custom lockscreen on your phone? These custom lockscreens have ads which allows them to earn from you and hence they share the ad revenues with you. Apps like Sidejoy, Adme, Fronto and Unlock & Win by Perk can be used for the purpose.
- Share and Earn : Some apps already have surveys, app installs and other methods but allow users to make money by inviting others to install the apps. This is done by sharing a referral code. Apps like AppNana, GetGiftz are popular in this category. Just use the invitation codes and share yours with others and exchange the points for real cash.
- Background Apps : Most passive way of making money is just by allowing your phone to run some apps in the background for many hours. If you have a spare phone, you can just keep running these apps 24/7 and watch your income grow. People make more than $300 per month with just this method. Most popular and recommended app in this category are Perk and ChargePay. Other examples include Your Panels, Screenwise Trends Panel, App Trailers etc.
- Watch TV Shows : Just check in TV shows with your device during the right time using audio recording for less than a minute and earn $10 a day. This was the idea of the Viggle app. You can watch TV shows that you like and can simply check in those pay more to earn cash. Perk also allows you to watch TV shows to earn money but I would recommend that you try out Viggle app.
- Tasks : Apps like Field Agent and Task Rabbit allow users to earn money doing real world tasks such as taking photos of products on walmart and pay users for the same. This also can be a good source of income provided you are free to take up those tasks.
- Test Apps : Ever wondered that just testing apps and giving reviews can earn you $50 a day? With websites like UserTesting, Trymyui, Youeye etc… you can earn around $10 per test and more than $50 a day for both Android and IOS apps. A lot of new app developers need honest opinion about their apps, this is where Testing app comes in.
- Cashback rewards : If you love shopping and would like to get discounts and offers, apps like Ibotta, ebates, mobee, reciept dogs make it better for you. You not only get the sale discount among the best offers in the city but you also get a cashback reward on every purchase which you can redeem to your Paypal or amazon gift card.
- Diet Plan : Wouldn’t it be amazing if you could get paid for losing weight and following right diet plan? This was the idea of the “Pact” app. This app prepares a diet plan, set of healthy activities and workout time for you and following the same makes you money. The catch however is that if you don’t follow the plan you lose money.
That was the top 10 list for making money with apps. If you have any questions regarding any of the apps above, you can comment below.
We would also like to inform you that the developer team of this blog is working on an amazing app for you to make money on which by the way can be more rewarding than any of the methods above. To get an email when it launches in app stores, please subscribe using the form on the left (in mobile) or on the right(in desktop).
For more updates like these, don’t forget to subscribe using your email.
Thanks a lot for reading. Enjoy!