javascript loop through array
array iteration styles illustrate programming paradigms
let newArray = []; const theArray = [2, 4, 6, 8, 10]
// 1) imperative, explicit
for (var i = 0; i < theArray.length; i++) { // var is mutable
console.log(theArray[i]); // side effect from writing to console
newArray[i] = theArray[i] * theArray[i] // let is mutable
}
// 2) forEach function of the Array class TIP: console.log(Array) //Does not change the array, Returns undefined
function f1(theValue, theIndex, originalArray) { numVal = numVal * theValue }
theArray.forEach(f1); console.log( ` creates ${ newArray }` );
run.addEventListener("click", function () {cpeople.forEach((element) => console.log(element.firstname));});
// 3) declarative, implicit
function f1(v,i,a) { v=v*v }
const constArray = theArray.map(fNumbers);
console.log( ` immutable ${ newArray }` );