What is the main purpose of if statements in programming?

The main purpose of if statements in programming is to make decisions based on Boolean conditions. An if statement evaluates a condition that results in either true or false. If the condition is true, the program will execute a specific block of code; if false, it may execute an alternative block or skip over it entirely. This decision-making capability is fundamental to creating dynamic and responsive programs, allowing for different outcomes based on varying inputs or states.

For example, in a program that processes user input, an if statement can be used to check if the input meets certain criteria (like being a valid age). Depending on the result of that check, the program can respond appropriately, such as alerting the user or processing the input further.

The other options focus on different aspects of programming. Defining the structure of the program refers more to overall architecture and organization rather than decision-making. Managing memory allocation pertains to how resources are utilized within a program, which is not related to conditional execution. Storing data for later use relates to data handling and storage, which is also outside the scope of what if statements do.