Learned about Closures, how to encapsulate data, Multiple closures an…

…d Loops in closures

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/04_intro_to_closures.js

@@ -0,0 +1,20 @@
+// Closures
+
+// Simple Closure
+
+function outerFunction(){
+    const outerVar = "I am Outside!"
+
+    function innerFunction(){
+
+        console.log(outerVar);
+    }
+
+    return innerFunction;
+}
+
+const closureFunction = outerFunction()
+closureFunction(); // I am outside
+
+// In this example, innerFunction is a closure.
+// It captures variable outerVar from it's lexical scope and retains access to it even after outerFunction has finished executing.

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/05_data_encapsulation_with_closure.js

@@ -0,0 +1,18 @@
+// Data Encapsulation with Closures
+
+function createCounter(){
+
+    let count = 0;
+
+    return function(){
+        count += 1
+        return count
+    }
+}
+
+const counter = createCounter()
+console.log(counter()) // 1
+console.log(counter()) // 1
+console.log(counter()) // 3
+
+// In this example, 'count' is encapsulated within the function returned by createCounter, allowing it to maintain state between calls.

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/06_multiple_closures.js

@@ -0,0 +1,26 @@
+// Multiple Closures
+
+function createAdder(x){
+    return function(y){
+        return x + y
+    }
+}
+
+const addFive = createAdder(5)
+
+const addTen = createAdder(10)
+
+console.log(addFive(2)) // Output: 7
+
+console.log(addTen(7)) // Output: 17
+
+
+function fullName(firstName){
+    return function(lastName){
+        return `${firstName} ${lastName}`
+    }
+}
+
+const myName = fullName('Sohail')
+
+console.log(myName("Shaikh")); // Sohail Shaikh

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/07_closure_in_loops.js

@@ -0,0 +1,26 @@
+// Closure in Loops
+
+// Incorrect behavior
+var funcs = []
+for(var i = 0; i < 3; i++){
+    funcs[i] = function(){
+        console.log(i);
+    }
+}
+
+funcs[0]() // 3
+funcs[1]() // 3
+funcs[2]() // 3
+
+
+// Corrected with let
+
+for(let i = 0; i < 3; i++){
+    funcs[i] = function(){
+        console.log(i);
+    }
+}
+
+funcs[0]() // 0
+funcs[1]() // 1
+funcs[2]() // 2