There might be reasons to use `bc` like this if you don't know the type of `age` and it could be a non-numeric string. Buuuuut a programming language where a simple integer-comparison leads to two subprocesses is going to be slower than the slowest existing programming languages, by orders of magnitude.
// Define variables
let name = "John"
let age = 30
// Display a greeting
echo "Hello, my name is {name}"
// Perform conditional checks
if age < 18 {
echo "I'm not an adult yet"
} else {
echo "I'm an adult"
}
So there is no input, everything is known statically. No sanitation required. Any additional checks done by amber in the bash code is unnecessary.