integer

Kotlin: A for loop that counts up to some maximum integer value

As a brief note to self, I was just converting some Java code to Kotlin, and the correct way to convert this Java for loop that uses i as a counter:

for (int i=0; i<tabLayout.tabCount; i++) { ...

is with this Kotlin for loop:

for (i in 0 until tabLayout.tabCount) { ...

The key there for me is the 0 until part of the syntax.

How to get the current year as an integer in Scala

Scala FAQ: How do I get the current year as an integer (Int value) in Scala?

Solution: Use the Java 8 Year or LocalDate classes, or the older old Java Calendar class. The solutions are shown below.

How to create a Java or Scala date from a Long value

Scala FAQ: How do I created a Scala Date from a Long value? When I give the Java Date class constructor a Long value it returns a date from 1970.

Solution: You need to multiply the Long value by 1000, and also make sure you pass a Long value into the Date constructor. The Scala REPL shows how this works:

A Java method to determine if an integer is between a range

Last night I was writing some code for my Android football game, and decided it would be best if I had a between method, so I could write some code like this to show that I wanted to test to see if a number was between an integer range:

if (between(distance, 8, 10)) { ...

That could would be interpreted as, “If the distance is between the values 8 and 10, do whatever is in the code block.” (I can make that code more readable in Scala, but in Java I think that’s the best I can do.)

Java: How to round a float or double to an integer alvin December 25, 2015 - 3:50pm

Java math FAQ: How do I round a float or double to an integer in Java?

Solution: Use Math.round() to round a float (or double) to the nearest integer (int) in Java.

You can see how this works in the examples that follow, where the result is shown in the comment after each line: