Answers for "closure example in javascript"

closure in javascript

// closure in javascript
-> A closure gives you access to an outer function’s scope
   from an inner function

const outerFun = (a) => {
  let b = 10;
  // inner func can use variable/parameter of outer funcion
  const innerFun = () => {
    let sum = a + b; 
    console.log(sum);
  }
  return innerFun;
}
let inner = outerFun(5);
inner();

js closure examples

function outer() {
  var counter = 0; // Backpack or Closure
  function incrementCounter() {
    return counter++;
  }
  return incrementCounter;
}

const count = outer();
count(); // 0
count(); // 1
count(); // 2

what is closure in javascript

function OuterFunction() {

    var outerVariable = 100;

    function InnerFunction() {
        alert(outerVariable);
    }

    return InnerFunction;
}
var innerFunc = OuterFunction();

closure in javascript

function makeFunc() {
  var name = 'Mozilla';
  function displayName() {
    alert(name);
  }
  return displayName;
}

var myFunc = makeFunc();
myFunc();

What is Closures in JavaScript

/*A closure is the combination of a function bundled together (enclosed) with references
to its surrounding state (the lexical environment). In other words, a closure gives you 
access to an outer function’s scope from an inner function. In JavaScript, closures are 
created every time a function is created, at function creation time.*/

function init() {
  var name = 'Mozilla'; // name is a local variable created by init
  function displayName() { // displayName() is the inner function, a closure
    alert(name); // use variable declared in the parent function
  }
  displayName();
}
init();

closure in javascript

var counter = (function() {
  var privateCounter = 0;
  function changeBy(val) {
    privateCounter += val;
  }
  return {
    increment: function() {
      changeBy(1);
    },
    decrement: function() {
      changeBy(-1);
    },
    value: function() {
      return privateCounter;
    }
  };
})();

console.log(counter.value()); // logs 0
counter.increment();
counter.increment();
console.log(counter.value()); // logs 2
counter.decrement();
console.log(counter.value()); // logs 1