how to have a function in variable in js code example

Example 1: declare function javascript

function myFunction(var1, var2) {
  return var1 * var2;
}

Example 2: javascript function declaration

//Four ways to declare a function
function add(a, b) {
  return a + b;
}

var add = function(a, b) {
  return a + b;
}

var add = (a, b) => {
  return a + b;
}

var add = (a, b) => a + b;