Data types
The byte data type can store whole numbers from -128 to 127. This can be used instead of int or other integer types to save memory when you are certain that the value will be within -128 and 127:
Example
public class Main {
public static void main(String[] args) {
byte myNum = 126;
System.out.println(myNum);
}
}
Short
The short data type can store whole numbers from -32768 to 32767:
Example
public class Main {
public static void main(String[] args) {
short myNum = 31000;
System.out.println(myNum);
}
}
Int
The int data type can store whole numbers from -2147483648 to 2147483647. In general, and in our tutorial, the int data type is the preferred data type when we create variables with a numeric value.
public class Main {
public static void main(String[] args) {
int myNum = 100000;
System.out.println(myNum);
}
}
Float
The float data type can store fractional numbers from 3.4e−038 to 3.4e+038. Note that you should end the value with an “f”:
public class Main {
public static void main(String[] args) {
float myNum = 5.75f;
System.out.println(myNum);
}
}
Double
The double data type can store fractional numbers from 1.7e−308 to 1.7e+308. Note that you should end the value with a “d”:
public class Main {
public static void main(String[] args) {
double myNum = 19.99d;
System.out.println(myNum);
}
}
Characters
The char data type is used to store a single character. The character must be surrounded by single quotes, like ‘A’ or ‘c’:
public class Main {
public static void main(String[] args) {
char myGrade = ‘B’;
System.out.println(myGrade);
}
}