It is considered good practice not to hardcode any values into the module, but to pass them as a parameter of the module itself (that is, as a parameter of the function called in-place):
;(function(arg1, arg2) { // the parameters get into variables
})(1, 2); // passing some parameters
Let's look at an example. Let's have a div with a number and a button:
<div id="div">3</div>
<button id="btn">click me</button>
Suppose we also have some module:
;(function() {
let div = document.querySelector('#div');
let btn = document.querySelector('#btn');
function func(num) {
return num * num;
}
btn.addEventListener('click', function() {
div.textContent = func(div.textContent);
});
})();
As you can see, our element selectors are hardcoded in the module code. A better solution would be to pass them as module parameters - so in the future we can easily change them. Let's refactor our module:
;(function(selector1, selector2) {
let div = document.querySelector(selector1);
let btn = document.querySelector(selector2);
function func(num) {
return num * num;
}
btn.addEventListener('click', function() {
div.textContent = func(div.textContent);
});
})('#div', '#btn');
Given a button and three inputs into which numbers are entered. On pressing the button print the sum of the entered numbers to the console. Implement a task using a module.