JS Lab 3 - ASAT 2023

lab3-closure.js

function outer() {
  var a = 10;
  function inner() {
    console.log(a);
  }
  return inner;
}
const x = outer();
x();   // ? 

// ---------------------------------------

function multiplyBy(x) {
  return function (y) {
    return x * y;
  };
}
const double = multiplyBy(2);
console.log(double(5)); // ?

// ---------------------------------------

function outer() {
  var count = 0;
  return function() {
    count++;
    return count;
  };
}
const increment = outer();
console.log(increment() + increment());  // ?
 
// ---------------------------------------

function buildMessage(message) {
  return function (name) {
    return `${message}, ${name}!`;
  };
}
const greet = buildMessage("Hello");
console.log(greet("Alice")); // ?

// ---------------------------------------

var funcs = [];
for (var i = 0; i < 3; i++) {
  funcs.push(function() {
    console.log(i);
  });
}
funcs[2](); // ?

// --------------------------------------- 

function outer() {
  var a = 5;
  function inner() {
    a++;
    console.log(a);
  }
  return inner;
}
const incrementA = outer();
incrementA();  // ? 
incrementA();  // ?

// ---------------------------------------

function countdown(n) {
  return function () {
    console.log(n);
    n--;
  };
}
const counter = countdown(3);
counter(); // ?
counter(); // ?


// ---------------------------------------

var number = 10;
function outer() {
  var number = 5;
  return function() {
    console.log(number);
  };
}
const display = outer();
display(); // ?

// ---------------------------------------

function makeCounter(start, step) {
  var count = start;
  return function () {
    var current = count;
    count += step;
    return current;
  };
}
const counter = makeCounter(1, 2);
console.log(counter() + counter()); // ?