import example

add_two.zig

@@ -1,6 +1,10 @@
 
+extern fn print(i32) void;
+
+
 //pub fn add_two(a: i32, b: i32) i32 {
 export fn add_two(a: i32, b: i32) i32 {
+  print(a + b);
   return a + b;
 }
 

index.html

@@ -15,7 +15,9 @@ function test1(ex){
 }
 
 window.addEventListener("load", function(){
-  var env = { env: {} };
+  var env = { env: {
+    print: (result) => { console.log('result = ', result); }
+  } };
   WebAssembly.instantiateStreaming( fetch('add_two.wasm'), env).then( result => {
     console.log('WASM loaded!');
     var ex = result.instance.exports;