Conditionals & Logic
Learn how to use conditionals and logic to build programs that generate different outcomes.
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Key Concepts
Review core concepts you need to learn to master this subject
if Statement
if Statement
if (a == 10) {
// Code goes here
}An if statement is used to test an expression for truth.
- If the condition evaluates to
true, then the code within the block is executed; otherwise, it will be skipped.
else Clause
else Clause
if (a == 10) {
// Code goes here
}An else clause can be added to an if statement.
- If the condition evaluates to
true, code in theifpart is executed. - If the condition evaluates to
false, code in theelsepart is executed.
switch Statement
switch Statement
if (a == 10) {
// Code goes here
}A switch statement provides a means of checking an expression against various cases. If there is a match, the code within starts to execute. The break keyword can be used to terminate a case.
default is executed when no case matches.
Relational Operators
Relational Operators
if (a == 10) {
// Code goes here
}Relational operators are used to compare two values and return true or false depending on the comparison:
==equal to!=not equal to>greater than<less than>=greater than or equal to<=less than or equal to
else if Statement
else if Statement
if (a == 10) {
// Code goes here
}One or more else if statements can be added in between the if and else to provide additional condition(s) to check.
Logical Operators
Logical Operators
if (a == 10) {
// Code goes here
}Logical operators can be used to combine two different conditions.
&&requires both to be true (and)||requires either to be true (or)!negates the result (not)
- 1Every program we’ve seen so far has only had one possible path of execution — they all execute line by line, from top to bottom. And every time you run one of those programs, it gives you the same …
- 2Before we dive deep into the syntax of the if statement, let’s do a demo! Here, we have coinflip.cpp program that simulates a coin toss: - 50% of the time, it’s Heads. - 50% of the time, i…
- 3An if statement is used to test an expression for truth and execute some code based on it. Here’s a simple form of the if statement: if (condition) { some code } If the condition is true, …
- 4When writing conditional statements, sometimes we need to use different types of operators to compare values. These operators are called relational operators. To have a condition, we need relati…
- 5We can also add an else clause to an if statement to provide code that will only be executed if the condition is false. Here’s a form of an if statement that includes an else clause: if (condition…
- 7Now that we know how if, else if, else work, we can write programs that have multiple outcomes. Programs with multiple outcomes are so common that C++ provides a special statement for it… the swi…
- 1Often, when we are trying to create a control flow for our program, we’ll encounter situations where the logic cannot be satisfied with a single condition. Logical operators are used to combine …
- 2The and logical operator is denoted by &&. It returns true if the condition on the left and the condition on the right are both true. Otherwise, it returns false. Here’s the truth table: | a …
- 3The or logical operator is denoted by ||. It returns true when the condition on the left is true or the condition on the right is true. Only one of them needs to be true. Here’s the truth table…
- 4The not logical operator is denoted by !. It reverses the bool outcome of the expression that immediately follows. Here’s the truth table: | a | !a | | — | — | | false | true | | true | fals…
What you'll create
Portfolio projects that showcase your new skills
Magic 8-Ball
We've learned a powerful tool in C++ — control flow! It's so powerful, in fact, that it can be used to tell someone's fortune.
Harry Potter Sorting Hat Quiz
Write a program that asks the user some questions and places them into one of the four Houses!
Rock, Paper, Scissors, Lizard, Spock
The Big Bang Theory Edition!
How you'll master it
Stress-test your knowledge with quizzes that help commit syntax to memory
Conditionals & Logic
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