What does the decrement operator do?

The decrement operator is a unary operator that reduces the value of a variable by 1. When applied, it directly modifies the variable, ensuring that its new value is one less than its original value. This is particularly useful in programming when you need to perform countdowns, loop iterations, or when managing arrays and other data structures that require indexing backwards.

In this context, the other options do not accurately describe the function of the decrement operator. The first option suggests an increase in value, while the third and fourth options imply multiplication and division, respectively, which are unrelated operations. Thus, the definition of the decrement operator as a means to subtract 1 is both precise and essential for understanding how it operates within the context of programming.