What is the purpose of casting in programming?

Casting in programming primarily serves the purpose of converting a value from one data type to another. This is especially important in languages like Java, where strict type checking is enforced. For instance, if you have a floating-point number (like 3.14) and you need to use it as an integer, you would use casting to convert that float to an integer type. This allows the runtime to understand how to handle the variable and ensures that operations on different types are performed correctly.

Casting can also be used in situations where you want to forcefully change a variable's type, even if it results in data loss (as observable when converting from a float to an int, where the decimal part is discarded).

In contrast, modifying an existing variable refers to updating its value without changing its type. Declaring constant values is related to defining variables that cannot change after being initialized, while incrementing a variable's value involves increasing its current value without any type transformation. Each of these options addresses different operations, thereby highlighting the specific role of casting as a means of data type conversion.