Raw use of parameterized class
in the definition of method getStaticFieldValues() change: to
Java
Java way to check if a string is palindrome
Using reverse is overkill because you don’t need to generate an extra string, you just need to query the existing one. The following example checks the first and last characters are the same, and then walks further inside the string checking the results each time. It returns as soon as s is not a palindrome. The problem with the reverse approach … Read more
How Exactly Does @param Work – Java
@param won’t affect the number. It’s just for making javadocs. More on javadoc: http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html
Java: using switch statement with enum under subclass
Change it to this: The clue is in the error. You don’t need to qualify case labels with the enum type, just its value.
Java Hashmap: How to get key from value?
If you choose to use the Commons Collections library instead of the standard Java Collections framework, you can achieve this with ease. The BidiMap interface in the Collections library is a bi-directional map, allowing you to map a key to a value (like normal maps), and also to map a value to a key, thus allowing you to perform … Read more
How to check if an int is a null
An int is not null, it may be 0 if not initialized. If you want an integer to be able to be null, you need to use Integer instead of int. Besides the statement if(person.equals(null)) can’t be true, because if person is null, then a NullPointerException will be thrown. So the correct expression is if (person == null)
catDog string problem at Codingbat.com
While you are pretty close to a solution, there are a few critical problems in your code: Your call to substring() fetches a string of size 2. That string can never be cat nor dog. Change the second parameter in the method call to i + 3 to get 3 characters. Your call to substring() will throw an IndexOutOfRangeException, as i approaches the end of the length of the input string. Make … Read more
How does a Breadth-First Search work when looking for Shortest Path?
Technically, Breadth-first search (BFS) by itself does not let you find the shortest path, simply because BFS is not looking for a shortest path: BFS describes a strategy for searching a graph, but it does not say that you must search for anything in particular. Dijkstra’s algorithm adapts BFS to let you find single-source shortest paths. … Read more
Java Installation Not Completed / Unable to install Java
One of your files is corrupted. Simply download Jarfix and run it. The Breakdown has an easy and helpful website to using Jarfix. Simply follow the instructions and download it in the link below:
Error: Could not find or load main class in intelliJ IDE
This might help: 1) “Build” menu -> “Rebuild Project“. Sometimes Intellij doesn’t rewrite the classes because they already exist, this way you ask Intellij to rewrite everything. 2) “Run” menu -> “Edit configuration” -> delete the profile -> add back the profile (“Application” if it’s a Java application), choose your main class from the “Main … Read more