Statements

if / else

if x > 0 {
    Print("positive");
} else if x < 0 {
    Print("negative");
} else {
    Print("zero");
}

match

match performs exhaustive pattern matching. The compiler requires all cases to be covered.

match status {
    200 => Print("OK"),
    404 => Print("Not Found"),
    500 => Print("Server Error"),
    _   => Print("Unknown"),
}

// Literal patterns
match code {
    0    => Print("zero"),
    1..9 => Print("single digit"),
    _    => Print("other"),
}

// Enum destructuring
match event {
    Event.Click(x, y)   => HandleClick(x, y),
    Event.KeyPress(key) => HandleKey(key),
    Event.Quit          => Exit(),
}

// Struct destructuring
match point {
    Point { x: 0, y: 0 } => Print("origin"),
    Point { x, y }       => Print(x, y),
}

// Guards
match temperature {
    t if t < 0.0   => Print("freezing"),
    t if t < 20.0  => Print("cold"),
    t if t < 30.0  => Print("comfortable"),
    _              => Print("hot"),
}

The wildcard _ matches any value and discards it. Patterns are checked in order; the first matching arm executes.

while

var i = 0;
while i < 10 {
    Print(i);
    i++;
}

for / in

for item in collection {
    Print(item);
}

for i in 0..10 {
    Print(i);  // prints 0 through 9
}

for i in 0...10 {
    Print(i); // prints 0 through 10 (inclusive)
}

break

while true {
    let input = ReadLine();
    if input == "quit" break;
    if input == "" continue;
    Process(input);
}

continue

while true {
    let input = ReadLine();
    if input == "quit" break;
    if input == "" continue;
    Process(input);
}