Problem scenario
You want to pass an argument to another piece of code (e.g., a function in Java). How do you pass an array as a parameter to another portion of code?

Solution
Java only has methods — not functions (according to this posting).

This code (which should be called contInt.java) will pass a two-dimensional array called twoD to the method “coolp”.

…

Continue reading “How Do You Pass an Array to a Method in Java?”

Problem scenario
You are trying to print out a multi-dimensional array in Java. When you try to compile your program, you get this:

error: no suitable method found for toString(String)
System.out.println(Arrays.toString(Arrays.toString(var1)));
^
method Arrays.toString(long[]) is not applicable
(argument mismatch; String cannot be converted to long[])

What should you do?

Solution
You need to pass a one-dimensional array to Arrays.toString in the System.out.println statement.

…

Continue reading “How Do You Troubleshoot “error: no suitable method found for toString(String)”?”

Problem scenario
You have a public static void main (String[] args) portion of your Java program. You want to have a subroutine such as a function outside of this section. How do you code this?

Solution
In Java methods are components of an object that perform an action on the object themselves. We therefore use the term “method” here and not “function”.

…

Continue reading “How Do You Create a Callable Function in Java outside of the “main” Section?”

Problem scenario
You are trying to run your Java program from a .jar file. You get an error like this:

Error: Could not find or load main class target.contint-0.1.0.jar
Caused by: java.lang.ClassNotFoundException: target.contint-0.1.0.jar

What should you do?

Solution
Examine the mainClass stanza. The word to the left of the period should be the name of the package.

…

Continue reading “How Do You Troubleshoot a pom.xml File?”

Problem scenario
You try to compile a java program, but you get this error:

hello.java:1: error: class HelloWorld is public, should be declared in a file named HelloWorld.java
public class HelloWorld {
^
1 error

What is wrong?

Solution
The .java file must have a name of “HelloWorld” like the public class in the error.

…

Continue reading “How Do You Troubleshoot a Java Compilation Error “class fooBar is public, should be declared public class…”?”

Problem scenario
You want to create a basic Java program that can read alphanumeric input interactively. How do you write such a program?

Solution
1. Verify the “javac” command works. Run “man javac” to see the man page. If you do not get a man page, install the Java development tools. On a RedHat derivative, run this: sudo yum -y install java-devel

2.

…

Continue reading “How Do You Write a Java Program to Read in Letters and Numbers?”