how to use spread to add to array code example

Example 1: spread operator javascript

const parts = ['shoulders', 'knees']; 
const lyrics = ['head', ...parts, 'and', 'toes']; 
//  ["head", "shoulders", "knees", "and", "toes"]

Example 2: ellipsis javascript

/* Spread syntax ( ex. ...arrayName) allows an iterable such as an array expression or string 
to be expanded in places where zero or more arguments (for function calls) 
elements (for array literals) are expected, or an object expression to be 
expanded in places where zero or more key-value pairs (for object literals) 
are expected. */


//example
function sum(x, y, z) {
  return x + y + z;
}

const numbers = [1, 2, 3];

console.log(sum(...numbers));
// expected output: 6