This question already has answers here:
Java equivalent of unsigned long long?
(10 answers)
Closed 6 years ago.
A simple question:
Can someone help me declare a long long array in Java?
I've tried to cast it, but no luck:
(long long)[] sum = new (long long)[10];
Also, I searched across the internet and didn't really find anyone who uses long long to define an array
Any help please?
I do not know a type called "long long".
Are you sure the code you read was written in Java? Maybe it was a JNI routine that was called into?
it isn't also listed here: http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
There is no long long type in Java.
If you need an arbitrarily-long integer type, you can use BigInteger, but this is a reference type, and has no "convenient" operators like +.
long long is not a valid type in java
using a big integer would make more sense in this case...
BigInteger[] sum = new BigInteger[10];
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:
What does a 'int' in parenthesis mean when giving a value to an int?
(7 answers)
Closed 2 years ago.
What does the second line in the following code represent?
long longNumber = Integer.MAX_VALUE;
int intNumber = (int) longNumber;
I've created a longNumber and assigned it MAX_VALUE. What does the second line mean?
Thanks in advance.
Writing "(Generic Type) VariableName" mean that you are changing the type of "VariableName"
this syntax is called "CASTING"
In this case you are converting a Long variable to an Int variable.
Casting is not always a secure method becouse if the LONG number is higher than Integer.maxvalue the number will NOT be converted in the correct way (becouse LONG type has more bits than normal INT)
This question already has answers here:
what is difference between integer a = 5 and new Integer(5)?
(5 answers)
Closed 8 years ago.
I understand that an identical question has been asked before-
what is difference between integer a = 5 and new Integer(5)?
However, none of the answers is satisfactory to me-
My question is simply this-
If I say Integer i = 23; it is clearly creating an object i of type Integer. All the Integer methods are available to it. So why is it different from an explicit instantiation- Integer i = new Integer(23) ?
Any insight into this will be much appreciated.
If I say Integer i = 23; it is clearly creating an object i of type Integer.
No, it returns a reference to an object of type Integer. Whether a new one is created or an existing one (from the JVM's constant pool) is re-used is at the discretion of your JVM.
For int literal values from the range –128 to 127 it is even required that Integer constants are pooled and a new instance never be created.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
What is the size of a boolean variable in java?
Java - boolean primitive type - size
A boolean value is a single-on off and could be represented in one bit. However, I have read that a language often uses more bytes are them to be accessed more efficiently.
What is the specific number of bytes in Java?
Oracle has a complete list of the data-types and sizes here:
http://download.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Unfortunately, that page states:
This data type represents one bit of information, but its "size" isn't
something that's precisely defined.
This answer seems to provide the reasoning of why the size isn't precisely defined.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
In Java, can I define an integer constant in binary format?
In python, you can do something like:
a = 0b00000010 which would set a to 2.
Is it possible to do something like that in Java? I know I could just go through and assign my varibles by the number instead of binary, but I like the visual.
Thanks ~Aedon
In Java 7, you can do
int a = 0b00000010;
However if you're working with an older version, I'm afraid you're stuck with
int a = Integer.parseInt("00000010", 2);