Guard

A guard in programming is a conditional check that helps ensure certain conditions are met before executing specific code. It acts as a gatekeeper, preventing errors by verifying inputs, states, or assumptions early. If the condition isn't satisfied, the guard typically halts further execution or handles the issue gracefully. This approach improves code safety, readability, and robustness, making it easier to manage and debug. Essentially, guards establish safe boundaries in code to avoid unexpected behaviors or crashes caused by invalid data or states.