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closure.js
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47 lines (36 loc) · 1.19 KB
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// ==== Challenge 1: Write your own closure ====
// Write a simple closure of your own creation. Keep it simple!
let position = "Seated";
let state = "in anticipation.";
let status = () => {return `${position} ${state} Hooray!`;};
console.log(status());
// ==== Challenge 2: Create a counter function ====
let num = 0;
const counter = () => {
// Return a function that when invoked increments and returns a counter variable.
return num +=1;
};
const newCounter = counter;
newCounter();
newCounter();
newCounter();
newCounter();
console.log(num);
// Example usage: const newCounter = counter();
// newCounter(); // 1
// newCounter(); // 2
// ==== Challenge 3: Create a counter function with an object that can increment and decrement ====
let num =0;
const counterFactory = () => {
// Return an object that has two methods called `increment` and `decrement`.
// `increment` should increment a counter variable in closure scope and return it.
// `decrement` should decrement the counter variable and return it.
return {
increment: () => {return num+=1;},
decrement: () => {return num-=1;}
};
};
let x = counterFactory();
x.decrement();
x.decrement();
console.log(num);