Condicionales

What are conditionals in programming?

Conditionals are one of the fundamental pillars of programming. They allow our code to execute certain actions depending on whether or not a condition we define is met. Imagine that you want to display a message to the user depending on whether a student passed an exam based on his or her grade. If the grade is greater than or equal to a certain number, we display a pass message; otherwise, we display a fail message.

How is a conditional structured in Swift?

In Swift, the basic structure of a conditional begins with the word if, followed by the condition to be evaluated in parentheses. If the condition is met, the block of code between braces will be executed. If the condition is not met and we want to execute another block of code, we use the word else.

let note = 3 if note > 3 { print("It is greater than three") } else { print("It is not greater than three") }

How are mathematical operators used in conditionals?

Mathematical operators are essential for making comparisons within conditionals. Some examples are:

• > Greater than
• >= Greater than or equal to
• < Less than
• <= Less than or equal to
• == Equal to
• != Different from

These operators allow us to evaluate complex conditions and determine which set of instructions to execute.

if note >= 3 { print("Is greater than or equal to three") } else { print("Is not greater than or equal to three") }

How to evaluate multiple conditions?

Sometimes, we need to evaluate more than one condition to decide what actions to take. In these cases, it is common to use else if to include additional conditions.

let exempted = true if exempted || grade >= 3 { print("Congratulations, you passed the exam") } else { print("Sorry, see you next semester") } }

How to create complex conditionals?

For conditionals that require evaluating within certain ranges or several conditions at once, we can use grouping and logical operators.

let presento = true if presento && (exempted || grade >= 3) { print("Congratulations, you passed the exam") } else { print("Sorry, you didn't pass") } }

Implementing complex conditionals

We can construct complex conditionals one after another to, for example, determine the quality of a grade.

let gradeTwo = 4 if gradeTwo >= 0 && gradeTwo < 2 { print("You did very poorly on the exam.") } else if noteTwo >= 2 &&& noteTwo < 3 { print("Sorry, that was close") } else if noteTwo >= 3 && noteTwo < 4 { print("You passed, but you can do better") } else if noteTwo >= 4 && noteTwo <= 5 { print("Congratulations, you did very well") } else { print("System error") }

Test your knowledge by evaluating the equivalence of two strings in Swift. How would you handle sentence comparison? Share your ideas and experiences in the comments.