1. Declaring Variables:
In Java, a variable must be declared before it is used. The syntax for declaring a variable involves specifying its data type and giving it a name.
For example:
int age; // Declaration of an integer variable named 'age'
In Java, a variable must be declared before it is used. The syntax for declaring a variable involves specifying its data type and giving it a name.
For example:
int age; // Declaration of an integer variable named 'age'
2. Data Types in Java:
Java supports a rich set of data types including primitive types (e.g. int, double, char) and reference types (e.g. String, Object). Each data type has specific characteristics and is used for different scenarios.
- int number = 42; // Declaration and initialization of an integer variable
- double pi = 3.14; // Declaration and initialization of a double variable
- String message = "Hello, Java!"; // Declaration and initialization of a String variable
3. Variable Initialization:
Variables can be initialized during the declaration or they can be assigned values later in the program. It is good practice to initialize variables at the point of declaration to avoid unexpected behavior.
Variables can be initialized during the declaration or they can be assigned values later in the program. It is good practice to initialize variables at the point of declaration to avoid unexpected behavior.
- int count = 0; // Declaration and initialization
- count = 5; // Variable assignment
4. Variable Scope:
The scope of a variable determines where in the code it can be accessed. Java has three main types of variable scope:
Following naming conventions is crucial for writing readable and maintainable code. Variable names in Java should be meaningful, descriptive and follow the camelCase convention.
int studentAge; // Example of camelCase naming convention
The scope of a variable determines where in the code it can be accessed. Java has three main types of variable scope:
- Local Variables: Declared within a method or block and accessible only within that scope.
- Instance Variables: Belong to an instance of a class and are accessible throughout the entire class.
- Class (Static) Variables: Shared by all instances of a class and declared with the static keyword.
Following naming conventions is crucial for writing readable and maintainable code. Variable names in Java should be meaningful, descriptive and follow the camelCase convention.
int studentAge; // Example of camelCase naming convention
6. Final and Constants:
The final keyword is used to declare constants or variables that cannot be reassigned. Constants are typically declared using uppercase letters with underscores.
final int MAX_VALUE = 100; // Constant variable declaration
