This question already has answers here:
Generating Unique Random Numbers in Java
(21 answers)
Closed 9 years ago.
What would be the best way to generate 50,000 unique random values which are put into an ArrayList in Java?
Fill the ArrayList with 50,000 sequential values and call Collections.shuffle(list).
Related
This question already has answers here:
How do I declare and initialize an array in Java?
(31 answers)
Closed 2 years ago.
Can i ask whats the meaning of the input "52" on [], because if i delete the 52 the program wont run.
ArrayList<String> playerCard[]= new ArrayList[52];
The 52 tells the compiler how large the array is.
This question already has answers here:
How to create an array of 20 random bytes?
(6 answers)
Getting random numbers in Java [duplicate]
(2 answers)
Closed 3 years ago.
If java has a function similar to the function in python called urandom from the random library how can I use it?
Python you would do:
import random
random._urandom(1)
What can I do in java for this?
Urandom doesn't generate a random numbers, it returns n random bytes suitable for cryptographic use
Use:
byte[] bytes = new byte[x];
new Random().nextBytes(bytes);
Your array will then be filled with random bytes
This question already has answers here:
What is the difference between a HashMap and a TreeMap? [duplicate]
(8 answers)
Difference between HashMap, LinkedHashMap and TreeMap
(17 answers)
Closed 6 years ago.
In real time project, when we go for HashMap and TreeMap?
In what condition, we choose both?
There are also different data structure in Java Collection, so, what's the reason to use TreeMap or HashMap? and any short example?
This question already has answers here:
Is there a longer than int Java List?
(3 answers)
Using a long as ArrayList index in java
(7 answers)
Closed 7 years ago.
I want to have a big ArrayList, so its index would go beyond int, how or what can I use for that?
I already checked that Vector does have the same issue, any ideas?
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Java Remove Duplicates from an Array?
String={3333,4444,5555,5555,1111}
Using Delimiter i have put the String values in an array[]..
Now, How can i remove the same entries in an Array???
Use Set instead, Or use temporarily Set and get the unique result back to array
See
What interface in Java can I use to store unique objects?