rhai/doc/src/language/if.md

if Statement

{{#include ../links.md}}

if foo(x) {
    print("It's true!");
} else if bar == baz {
    print("It's true again!");
} else if ... {
        :
} else if ... {
        :
} else {
    print("It's finally false!");
}

All branches of an if statement must be enclosed within braces '{' .. '}', even when there is only one statement. Like Rust, there is no ambiguity regarding which if clause a statement belongs to.

if (decision) print("I've decided!");
//            ^ syntax error, expecting '{' in statement block

if-Expressions

Like Rust, if statements can also be used as expressions, replacing the ? : conditional operators in other C-like languages.

// The following is equivalent to C: int x = 1 + (decision ? 42 : 123) / 2;
let x = 1 + if decision { 42 } else { 123 } / 2;
x == 22;

let x = if decision { 42 }; // no else branch defaults to '()'
x == ();