integer

There are no ++ or -- operators in Scala (use += or -=)

In Scala there are no ++ or -- operators. You should instead use the += and -= operators, as shown below. First the += operator:

scala> var i = 1
i: Int = 1

scala> i++
<console>:9: error: value ++ is not a member of Int
              i++
               ^

scala> i += 1

scala> println(i)
2

Next the -= operator:

By Alvin Alexander on November 1, 2012

A PHP preg_match integer regex pattern matching example

PHP integer FAQ: Can you demonstrate a regular expression pattern to match an integer?

Interestingly, while reading a book titled Advanced PHP Programming, the author mentions that the PHP is_int function doesn't work exactly the way you expect it to. It just tests to see whether a given variable is typed as an integer or something else, so if you give it a string like "123", it will return false. This is a bad thing when you're trying to test web form data, for example.

By Alvin Alexander on December 4, 2010

A Perl random integer example

Perl random integer FAQ: Can you provide a Perl random integer example?

In my earlier Perl random tutorial, I described several different ways of generating random numbers in Perl. Today I'd like to share a Perl script I wrote that uses a random integer number to rotate files on this website.

A Perl random integer script example

The following Perl script performs the following functions:

By Alvin Alexander on May 18, 2011

Perl random numbers (tutorial, examples)

Perl random number FAQ: Can you show me some examples of how to get a random number in Perl?

Perl random number - solution

In its simplest form, if you just need a random decimal number between 0 and 1.0, you can use the Perl rand function like this:

# generate a random number in perl with the rand function

my $random_number = rand();
print $random_number, "\n";

When I save this Perl random number code to a file and run it three times, I get these results:

By Alvin Alexander on May 18, 2011

Perl array/sort FAQ - Perl integer array sorting

Summary: How to sort Perl arrays, in this case, a Perl integer array.

Sorting a Perl integer array (technically a Perl numeric array) is relatively simple, well, at least once you know the magic formula. The key thing to know is that you need to provide the Perl sort function a helper function (or block of code) that tells it how to sort integers. By default, the Perl sort function sorts arrays in ASCII order, and that's not going to work very well for you.

By Alvin Alexander on March 21, 2013

A simple Java Random class example

As I was digging around through some code today, I found the following Java Random class example, and thought I'd share it here for anyone needed to see how to work with the Random class in Java. This example shows how to generate a random number in Java that is greater than or equal to 0, and less than 100:

By Alvin Alexander on October 17, 2012

A Java int array example

Java array FAQ: How do you create an array of Java int values (i.e., a Java "int array")?

There are several ways to define an int array in Java; let's take a look at a few examples.

Java int array - Example 1

If you know the desired size of your array, an you'll be adding elements to your array some time later in your code, you can define a Java int array using this syntax:

By Alvin Alexander on February 28, 2013

Java - How to convert a String to a number

Question: How do I convert a String to an int or a float?

Here's a sample Java program that shows how to convert a String to either an int or a float:

By Alvin Alexander on October 17, 2012

A Java String to int conversion example

Here's a little Java code sample that shows how to try to perform a Java String to int conversion. In this example, if the conversion works, the variable pageNum will hold the int version of the pageNumString. If the conversion doesn't work a NumberFormatException will be thrown, and you'll need to deal with that.

By Alvin Alexander on October 17, 2012

A Java String to int conversion example

Java String to int FAQ: How do I convert a String to an int data type in Java?

Answer: You convert a String to an int using the parseInt method of the Java Integer class. The parseInt method converts the String to an int, and throws a NumberFormatException when the String can't be converted to an int type.

Let's take a look at two short examples.

By Alvin Alexander on February 21, 2013
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