In what cases and why is the catch construct used in exception handling?

The catch construct in C# is used to intercept and handle exceptions that may occur within a try block. It allows the program not to terminate abruptly due to errors, but to respond to them appropriately — for example, by displaying a message, performing alternative actions, or logging the issue.

Using catch is justified when there is a possibility of errors occurring during execution, such as when working with files, networks, databases, or user input.

Example:

try {
    int result = 10 / divisor; // may cause division by zero
} catch (DivideByZeroException ex) {
    Console.WriteLine("Error: division by zero.");
}

Here, catch catches the specific DivideByZeroException and handles it, preventing the program from crashing.