Write and run Go code in the browser compiled to WebAssembly with standard output display.
Go Playground (WASM) accepts a complete Go program, compiles it to WebAssembly in the browser, runs it, and displays text written to standard output. It is useful for checking small language experiments, formatting behavior, and deterministic calculations without invoking a local Go toolchain. The important boundary is the compilation target: a successful browser run demonstrates behavior under Go and WebAssembly in this page, not necessarily under a native executable. Code that assumes direct access to operating-system facilities can therefore be a poor fit even when its Go syntax is valid.
A concrete input and expected output from the current implementation.
Input
package main
import "fmt"
func main() {
a, b := 7, 5
fmt.Printf("%d + %d = %d\n", a, b, a+b)
fmt.Println("squares:", a*a, b*b)
} Expected output
7 + 5 = 12 squares: 49 25
Adding 7 and 5 produces 12. Multiplying each integer by itself produces 49 and 25; Printf formats the first line, while Println separates its arguments with spaces and terminates the second line.
The editor expects runnable Go source, so a minimal executable declares package main and defines func main(). Selecting Run compiles that program for WebAssembly and starts it inside the browser. Imports, declarations, and expressions must form a valid Go program. This is not an expression evaluator that automatically wraps a fragment such as 2 + 2.
The result area records what the running program writes to standard output. Calls such as fmt.Print, fmt.Println, and fmt.Printf therefore produce visible text, including their spacing and newline choices. Merely calculating or assigning a value produces no output line. Compilation and execution occur in the page, so the source is not uploaded for remote execution.
No. It is suited to self-contained code that can compile for the browser's WebAssembly target. Programs requiring an unavailable operating-system service, external command, device, or target-specific native behavior are outside its reliable scope. A compilation or runtime failure can reflect the target environment as well as a mistake in the source.
No. It can verify the displayed standard output and language-level result for this browser run. It does not establish identical filesystem access, networking, concurrency timing, memory use, or performance on linux/amd64 or another native target. Build and test in the intended deployment environment before relying on target-specific behavior.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
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