This question already has answers here:
What do 3 dots next to a parameter type mean in Java?
(9 answers)
Closed 7 years ago.
I have this AVL tree with a balance method:
private void setBalance(Node... nodes) {
for (Node n : nodes)
n.height = height(n.right) - height(n.left);
}
It uses a (...) syntax I have not encountered before. I can't find it on google or SO. It seems to be some type of list syntax, or array. Looks like something I would find in ruby.
Could someone knowledgeable in Java's syntax explain this code to me, and perhaps show me a version without the ... syntax?
Thanks.
These are varargs . Basically same are arrays but can be zero to many.
More info that might also assist.
Related
This question already has answers here:
How can I check if multiplying two numbers in Java will cause an overflow?
(15 answers)
Closed 1 year ago.
int ans = Integer.MAX_VALUE -(-1); //should I explicitly cast my method parameters in calculation to a wider bit type ?
Found a solution on searching the internet. An article that may help learners like me.
https://www.drdobbs.com/jvm/signalling-integer-overflows-in-java/210500001
This question already has answers here:
Pseudorandom Number Generator - Exponential Distribution
(9 answers)
Java exponential distribution
(1 answer)
Closed 5 years ago.
I am given a mean of 5. I need to generate a random number (exponentially distributed) in Java.
I know for Python, you can just run something like random.expovariate(5), but I'm not sure how to solve this for Java. Can anyone help me out?
see here. What you are looking for is something like this:
public double getNext() {
return Math.log(1-rand.nextDouble())/(-lambda);
}
(code taken from here)
This question already has answers here:
Find an array inside another larger array
(15 answers)
Closed 8 years ago.
Is there a way to find an array within another array like
a=[1,2,3,4,5,6,7]
b=[2,3,4]
c=[2,4,5]
// b is child of a, but c is NOT child of a.
Well I know that using Brute-force approach I can find the array within another array. But I want to know that is there any algo that can help me ... or (as I am using JAVA so) is there any built-in feature in JAVA that can help me ?
As already mentioned here :
https://stackoverflow.com/a/3940684/351861:
public static int findArray(Integer[] array, Integer[] subArray)
{
return Collections.indexOfSubList(Arrays.asList(array), Arrays.asList(subArray));
}
Java has builting features for that, apparently.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
How would I Evaluate a certain formula?
How would I split this formula into an array of characters each having their own number in the array:
a1+a2+a5*((a1+a6)*a3)
one I have added the spaces I am going to get column 1 because a1 will indicate column one and it will contain a number than I will add that to column 2. I am not allowed to use a tree or any of those other things just stacks and I have been asking that. But people keep telling me to use libraries and trees I am only in a 200 level course !
You need a grammar and a parser to do this in a general way. Something like this.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Java, 3 dots in parameters
public static void getImages(String... folders) throws IOException{
}
In the above getImages() method, why there is three dots. What is it mean? I searched google but couldn't find anything.
Yeah, punctuation is hard to search for if you don't know the technical term. In this case, it is varargs. Here is a nice link to explain it. Basically, the caller can add as many arguments as desired, and the method sees them arriving as an array of that length.