Learned about closures with asynchronous code, partial application an…

…d currying and how to preserve states

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/08_closure_with_asynchronous.js

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+// Closure with Asynchronous Code
+
+function fetchData(url){
+
+    fetch(url)
+        .then(response => {
+            if (!response.ok) {
+                throw new Error(`Network response was not ok`)
+            }
+            return response.json()
+        })
+        .then(data => {
+            console.log(data);
+        })
+        .catch(error => {
+            console.log(
+              "There has been a problem with your fetch operation:",
+              error
+            );
+        })
+}
+
+fetchData("https://api.github.com/users/sohail019");

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/09_partial_applications_and_currying.js

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+// Partial applications and currying
+
+function multiply(x){
+    return function(y){
+        return x * y
+    }
+}
+
+
+const double = multiply(2)
+console.log(double(5)) // 10
+
+const triple = multiply(3)
+console.log(triple(5)) // 15
+
+// Here, multiply is curried function that returns a closure, allowing for partial application of the multiple operation.

03 - Chai aur Javascript/16 - Lexical Scoping and Closures/10_preserving_states.js

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+// Preserving States
+
+function makeToggle(){
+    let isOn = false
+
+    return function(){
+
+        isOn = !isOn
+        return isOn
+    }
+}
+
+const toggle = makeToggle();
+
+console.log(toggle()) // true
+console.log(toggle()) // false
+console.log(toggle()) // true
+
+// The makeToggle function creates a closure that preserves the isOn state across multiple calls, effectively toggling the state each time it is invoked.
+