Conditionals & Logic

Learn how to develop complex programs in Swift with conditionals and logical operators.

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Key Concepts

Review core concepts you need to learn to master this subject

if Statement

else Statement

else if Statement

Comparison Operators

Ternary Conditional Operator

switch Statement

switch Statement: Interval Matching

switch Statement: Compound Cases

`if` Statement

var halloween = true 

if halloween {
  print("Trick or treat!")
}

// Prints: Trick or treat!

An if statement executes a code block when its condition evaluates to true. If the condition is false, the code block does not execute.

Conditionals

Lesson 1 of 2

1
Introduction to Conditionals
On a daily basis, we’re faced with making decisions based on certain conditions; if the weather is beautiful, we’ll go for a walk, or if it’s rainy, we’ll stay in and code! In Swift, the ability …
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2
If Statement
The if statement is the most basic and fundamental type of conditional in Swift. It is used to execute some code when a given condition is true. The structure of an if statement is: if condition…
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3
Else Statement
A tool most commonly used together with an if statement is the else statement. An else statement is used to execute a block of code when the condition of an if statement is false. Think of the el…
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4
Comparison Operators
So far, our conditions have consisted of a single variable whose value is a Boolean, true or false. With the help of operators, we can expand on this and create conditions that utilize multiple val…
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5
Else If Statements
Until now, we’ve been working with conditionals that can handle only one condition. If that condition is met, our program follows one course of action, otherwise it follows another. Swift provide…
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6
Ternary Conditional Operator
A standard if/else statement can get pretty lengthy - at least 5 lines of code. Many developers prefer to keep their code as concise as possible and favor a shorter syntax. Swift allows us to minim…
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7
Switch Statement
Another type of conditional statement that exists in Swift is the switch statement. The switch statement is a popular programming tool used to check the value of a given expression against multip…
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8
Switch Statement: Interval Matching
One super power that the switch statement possesses, is its ability to match values to an expression that exist within intervals. An interval denotes a range used for checking whether a given val…
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9
Switch Statement: Compound Cases
Another noteworthy ability of the switch statement is its use of multiple values in a single case. These are known as compound cases. The switch statement will match each value within a compound …
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10
Switch Statement: where Clause
Another neat feature available for the cases of a switch statement is the where clause. The where clause allows for additional pattern matching for a given expression. It can also be used with lo…
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11
Review
Excellent work! In this lesson, we’ve learned the following concepts: - An if statement consists of a condition and code block that executes when the condition is true. - An else statement is im…
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