As defined in JavaScript, variables of var, let and const can be used, but only difference is var is stored automatically, in meanwhile, let and const are temporary to its block

app.post("/test", () => {
  var a = 1;
  return a;
});

app.get("/test", () => {
  return a;
});

💡 Variable definitions without identifier like a = 1 are upsert operation, also automatically stored.

Control Flow

nucleoid.run(() => {
  var a = 1;
  var b = a + 2;
  var c = b + 3;
});

Once a variable is defined like var a = 1 (this doesn't apply to let or const), the runtime does 3 major things. First, it places the var a in the graph and makes the connection between dependent variables.

Second, updates state with new values in order get affect

However, actual execution is different since variables are tracked in the graph.

state.a = 1;
state.b = state.a + 2;
state.c = state.b + 3;

and finally stores statements in the runtime-managed fs