Final answer:
Programmers use arrays to handle large sets of related variables efficiently, simplifying code management, and improving program performance through organized data manipulation.
Step-by-step explanation:
A programmer might want to use an array instead of simple variables to reduce the amount of code needed, especially when dealing with a large number of related variables. Arrays allow for the storage and manipulation of data sets using a single identifier and by indexing, which can make code more organized and efficient.
For example, instead of declaring individual variables for 100 students' grades, a single array named grades can be used with indices representing each student. This makes it much easier to perform operations like average calculation or sorting. Moreover, the use of arrays can improve the performance of the program by optimizing the use of memory and helping in the implementation of complex data structures like matrices and multidimensional data.