I don't understand why it returns 0, it is supposed to increment by 1, is there something I don't know about closures?
let i = 0;
const getRenderValue = function() {
return i++;
};
const Component = function() {
let hello = getRenderValue();
console.log(hello); // return 0, expected value 1
};
Component();
Your closure does increment the value of i by one. If you did console.log(i); instead of console.log(hello);, you'd be seeing 1 on screen as expected.
Your closure however returns the value of i prior to the increment as it returns i++: It is a property of the postfix increment i++ that it returns i before and not after the increment. Use the prefix increment ++i if you want to return the changed value.