Language Essentials

Language essentials

MatchBox implements a growing subset of BoxLang. These examples introduce common syntax; check compatibility and target differences before moving a JVM application.

Variables and strings

name = "MatchBox";
active = true;
versionCount = 3;
println("Hello, #name#!");
println("Built with " & name);

Variables are dynamically typed. Use & for concatenation and #expression# for interpolation in strings.

Arrays and structs

targets = ["native", "browser", "embedded"];
println(targets[1]); // arrays are 1-indexed
arrayAppend(targets, "wasi");

project = { name: "Hello", ready: true };
println(project.NAME); // struct keys are case-insensitive

lengths = arrayMap(targets, (target) => len(target));

Control flow and functions

for (target in targets) {
    if (target == "native") {
        println("Build an executable");
    } else {
        println("Explore " & target);
    }
}

function greet(name = "world") {
    return "Hello, " & name;
}

double = (number) => number * 2;
println(greet());
println(double(21));

MatchBox supports functions, closures, arrow functions, default arguments, and type hints. Other supported constructs include while, switch, break, continue, and conditional expressions; confirm behavior in the version and target you ship.

Classes and asynchronous work

class Product accessors="true" {
    property name;
    property price;
}

product = new Product();
product.setName("Widget");
println(product.getName());

future = runAsync(() => {
    sleep(100);
    return "done";
});
println(future.get());

The VM includes classes, inheritance, interfaces, exception handling, and cooperative fibers. Do not assume that every JVM threading, library, or host API is available. See the BoxLang language documentation for the broader language reference.