Conditional statements or conditional control structures allow a program to have different behaviors depending on certain conditions being met.
Intuitively, this mimics the way humans make simple decisions and act upon them. For example, reasoning about whether to go outside might look like:
- Condition: Is it raining outside?
- If it is raining outside, then bring an umbrella.
- Otherwise, do not bring an umbrella.
We could keep adding clauses to make our reasoning more sophisticated, such as “If it is sunny, then wear sunscreen”.
In programming, control flow is the order in which statements and instructions are executed. Programmers are able to change a program’s control flow using control structures such as conditionals.
Being able to alter a program’s control flow is powerful, as it lets us adapt a running program’s behavior depending on the state of the program. For example, suppose a user is using a banking application and wants to withdraw $500. We certainly want the application to behave differently depending on whether the user has $20 or $1000 in their bank account!