What does the assignment statement do?

The assignment statement is a fundamental concept in programming that specifically sets or re-sets the value of a variable. When you use an assignment statement in Java, you are effectively telling the program to store a particular value in a variable, which can then be used or modified later in the code.

For example, when you write int x = 5;, this statement not only creates a variable x but also assigns it the value of 5. If you later write x = 10;, the assignment statement updates x to now hold the value 10. This ability to change the value stored in a variable is essential for maintaining state and performing calculations or operations throughout the execution of a program.

The other options pertain to different concepts in programming. Defining a constant, creating a new data type, or performing type casting involves more specific operations that do not directly relate to the core purpose of an assignment statement. Therefore, the assignment statement is uniquely tied to the action of assigning values to variables, making it a key pillar of programming in Java.