calling a function from outside of a function in javascript

You can return an object, which wraps both the functions:

var camera = (function() {

  function a() {
    console.log('calling ..a');
  }

  function b() {
    console.log('calling ..b');
  }
  //exposing a and b as a public API
  return {a, b}
})();

//calling function a() from outside
camera.a();
camera.b();

Now you created a private scope for external so you need to create a public scope.

  var camera = (function () {
    
      function a(){
        console.log('calling ..a');
      }
    
      function b(){
        console.log('calling ..b');
      }
    
      return {
        a,
        b
      }
    
    })();
    
    //calling function a() from outside
    camera.a();

The key of that is return the public references of the function.

  return {
    a,
    b
  }

sorry this is coming late... Here's a way to go about it you can follow this link to get a clearer idea and get an idea of what I initially did wrong

    const axios = require("axios")
const shitty_code = async (address, number) => { 
  this.blue = "blue is bright";
  
  this.purple = async () => {
      const one_api_call = await axios.get(`https://one-wierd-api/${address}/${number}`).then((response) => {
    return response.data })
  }
...
  return this;
}

// to call the shitty_code method purple ----------------------
console.log(shitty_code("some_random_address", 12).then(async (e)=> {
const response = await e.purple()
console.log(response)
})) 

// it actually worked with the this keyword, yay🎉!

or in your case,

const camera = async () => {
    this.a = () => {
console.log('calling ..a');
}
    
     this.b = async () => {
    console.log('calling ..b');
}
    
      return this;
}



// calling the function...
camera().then((anything) => {
    anything.b();
})

my method looks like this

var global = function(){
    var obj = {
        one:function(x){
            console.log(x);
        },
        two:function(x){
            console.log(x);
        }
    }
    return obj;
}();
global.one('first function');
global.one('second function');