In this example we have String with rows some of them bigger than four characters and some of them smaller. We want to remove the smaller ones and then print the result. We use lines() method which create stream from Stream API and in which every element is a row from the string rows. Then … Read more
In this example we will see how to get sum of input numbers and then compare it to 100. First we will request from the user to write how many numbers need to be added. Then we make a for cycle in which we will get every number from the user input and add it … Read more
To find the perimeter of rectangle we need to have the height and the width. So we create Scanner and we require the user input two numbers. Then we use the formula for the perimeter of rectangle: 2 * (width + height) At the end we print the result.
In this example we will see how to convert minutes to seconds. First we ask how many minutes we want to convert to seconds. Then we use Scanner to get the next integer from the user input. After that we multiply by 60 because every minute have 60 seconds and print the end result.
The Java Double class is a wrapper class that provides an object representation of the primitive data type double. It allows you to perform various operations on double values by treating them as objects. The Double class provides a set of methods that enable you to perform common operations on double values, such as converting … Read more
The Java Long class is a wrapper class that provides an object representation of the primitive data type long. It allows you to perform various operations on long values by treating them as objects. The Long class provides a set of methods that enable you to perform common operations on long values, such as converting … Read more
The Java Integer class is a wrapper class that provides an object representation of the primitive data type int. It allows you to perform various operations on int values by treating them as objects. The Integer class provides a set of methods that enable you to perform common operations on int values, such as converting … Read more
If we want to measure time of code execution then we can get the time as long (in milliseconds) before and after specific code execution and find the difference which will give us the answer how long a code execution take. Lest see example program: And the result is:
Let’s see example of flatMap. This method is part of the Stream API. We can use when we have nested collections but need only one level (we need to remove the nested collections ) and merge all the elements in one single collection. Lets have a simple class Main: The result is:
Let’s see how to use map grouping by functionality with Java stream. We have GenericRecord class that hold the data of the person and also the addresses of the people. In many cases we want to split this information to Peron and Addresses and we want to remove the duplicate information. See how several time … Read more
