What is the syntax for declaring a variable in Java?

In Java, the syntax for declaring a variable involves specifying the data type followed by the variable name. Here's an in-depth explanation of the syntax:

1. Data Type: The data type represents the kind of value that the variable can hold. Java has several built-in data types, including primitive types (such as int, double, boolean) and reference types (such as String, Object, etc.). You can also create your own custom data types using classes and interfaces.
2. Variable Name: The variable name is an identifier that uniquely identifies the variable within its scope. It should follow certain naming conventions, such as starting with a letter, using camel case (e.g., myVariable), and avoiding reserved keywords.
3. Optional Initialization: You can optionally initialize the variable with an initial value using the assignment operator (=). The initial value should be compatible with the declared data type.

Here's an example to illustrate the syntax:

```
java`// Declare and initialize an integer variable
int myNumber = 10;

// Declare a double variable
double pi;

// Declare a String variable
String message;

// Declare multiple variables of the same type in a single line
int x, y, z;

// Declare a constant variable using the final keyword
final int MAX\_VALUE = 100;

// Declare a variable without initialization (default value is assigned)
boolean flag;`
```
It's important to note that variables in Java are strongly typed, which means their data type is explicitly declared and enforced. This helps ensure type safety and prevents incompatible operations on variables.

Additionally, variables in Java have a scope, which defines where the variable is accessible. The scope can be within a block of code, a method, a class, or globally within a program, depending on where the variable is declared.

Understanding the syntax for declaring variables is fundamental in Java programming, as it allows you to create and manipulate data in a structured and organized manner.