JavaScript if, for and functions

if is a decision. If the condition is true, the lines inside run.

const age = 18;
if (age >= 18) {
  console.log("open");
} else {
  console.log("closed");
}

for repeats the same work a set number of times. This example prints 1, 2 and 3.

for (let n = 1; n <= 3; n++) {
  console.log(n);
}

function ties a job to a name. Then you call that name.

function add(a, b) {
  return a + b;
}
console.log(add(2, 5));

What is the difference between if and else? if runs when the condition is true, else when it is not.

When do I need for? When the same command must run several times.

What does return give back? The result of the function. add(2, 5) returns 7.

const or let? const does not change later, let can change.