Conditions

There are three ways to perform conditional logic:

• If Statement - This is a regular if statement that can be used anywhere
• If Chain - This is syntactical sugar for pesky if-else chained together.
• Ternary Expression - This is a way to represent conditional logic within an expression.

The good ol' if statement that you may recognize from other modern programming languages:

if age >= 16 {
    echo "Welcome"
}

Let's add an else branch to the mix

if age >= 16 {
    echo "Welcome"
} else {
    echo "Entry not allowed"
}

Well... you may notice that this short and simple "if" condition takes up a lot of space. In Amber, there is a rule that allows you to use a : symbol where you intend to write only one statement, wherever you can write a block of code. This can be handy when you want to perform multiple conditions with a single statement each.

if age >= 16: echo "Welcome"
else: echo "Entry not allowed"

// Or

if age >= 16:
    echo "Welcome"
else:
    echo "Entry not allowed"

The if-chain is a simplification technique for a sequence of if-else blocks. Allow me to illustrate this concept.

You can express it as follows:

if {
    drink == "water" {
        echo "Have a natural, mineralized water"
    }
    drink == "cola" {
        echo "Here is your fresh cola"
    }
    else {
        echo "Sorry, we have none of that"
    }
}

// Alternatively, as previously mentioned:

if {
    drink == "water": echo "Have a natural, mineralized water"
    drink == "cola": echo "Here is your fresh cola"
    else: echo "Sorry, we have none of that"
}

Instead of the nested if-else structure:

if drink == "water" {
    echo "Have a natural, mineralized water"
} else {
    if drink == "cola" {
            echo "Here is your fresh cola"
    } else {
            echo "Sorry, we have none of that"
    }
}

This approach provides a more concise and readable structure for handling multiple conditions.

Imagine needing to swiftly determine a value to assign based on a straightforward condition. This is precisely where ternary expressions prove invaluable. Here's a concise example:

let candy = count > 1
    then "candies"
    else "candy"

echo "I have {count} {candy}"

The ternary expression can of course be inlined when the expressions inside are short.

let candy = count > 1 then "candies" else "candy"