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This is the EXLskills free and open-source Java Variables Micro Course. It guides learners via explanation, demonstration, and thorough practice, from no more than a basic understanding of Java, to a moderate level of understanding regarding Java variables and operators.

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Yes, this a 100% free course that you can contribute to on GitHub here!

One of the most commonly used primitive data types is integer, or in Java, int, which can represent any whole number between -2,147,483,648 and 2,147,483,647. View the example below to learn how to declare and use an int variable.

IntegerDataTypeExample.java

package exlcode;
public class IntegerDataTypeExample {
// int can be any integer between -2147483648 and 2147483647
public static int exampleVariableOne = 27;
public static int exampleVariableTwo = -27;
public static int exampleVariableThree = 100000;
public static void main(String[] args) {
System.out.println(exampleVariableOne);
System.out.println(exampleVariableTwo);
System.out.println(exampleVariableThree);
}
}

The integer data type is efficient and versatile; it should be used for any integer math. Notice that int must be a whole number. In case you were wondering, 0 is also a whole number. Assigning int to any non-whole number would cause an error.

In addition to what we see in the example above, we are also able to assign a value to an int by performing a mathematical operation with two numbers, such as int varOne = 10+10; will assign 20 to varOne. As with the other data types we have covered, we are using '=' so that the identifier points to a value it can store.

The negative aspect of the integer data type is if there are any equations that try to create a non-whole number with a decimal out of integer variables, the program will fail because int only allows whole numbers.