Start

Start is a special function that runs after the WebAssembly module is initialized. Let's take the same example that we used for the globals. We add the following content to globals.wat:

(module
    ; Code is elided
    (func $initMutableValue
          (global.set $mutableValue
               (i32.const 200))) 
     (start $initMutableValue)
)

We define the initMutableValue function, which sets mutableValue to 200. After that, we add a start block, which starts with startkeyword followed by the name of the function.

Note

The function referenced at the start should not return any value.

Let's use WABT to convert the WebAssembly text format into a WebAssembly module with the following command:

$ /path/to/wabt/bin/wat2wasm globals.wat

Let's run the example...