Creating Branches

A Single Branch -> if statement

let num = prompt("Enter a value");

if (num > 100) {
    console.log("Wow, that is a large number!");
}

console.log(`Your number is: ${num}`);

In this situation we created a single branch. The event that belongs to our if statement only executes if our given variable num is greater than 100.

Any code that belongs to a coding construct is called a "code block"

Binary Branch -> if ... else statement

To create a program with two pathways where we can have an event occurs when our if statement evaluates to false is using an else statement.

let num = prompt("Enter a value");

if (num > 100) {
    console.log("Wow, that is a large number!");
} else {
    console.log("Darn, that is a small number!");
}

console.log(`Your number is: ${num}`);

An else statement is not a requirement for all if clauses; however, you can use it if you want something to happen when the condition it is attached to is evaluated to false.

Multiple Branches

To create a program with multiple, BUT RELATED pathways, we can incorporate an else if statement.

let num = prompt("Enter a value");

if (num == 69) {
    console.log("Nice!");
} else if (num > 100) {
    console.log("Wow, that is a large number!");
} else {
    console.log("Darn, that is a small number!");
}

console.log(`Your number is: ${num}`);

The program above would work as follows

• It outputs Nice! only if num was equal to 69

• It outputs Wow, that is a large number!, only if num is not equal to 69 and greater than 100

• It outputs Darn, that is a small number!, only if num is not equal to 69 and num is less than 100

Recommended Reading

• Conditional Branching (Link)