chore: add more questions

Author: abhishekjakhar

docs/callbacks.md

@@ -340,3 +340,23 @@ The arguments object is a collection of parameter values pass in a function. It'
 It helps us know the number of arguments pass in a function.
 
 We can convert the arguments object into an array using the Array.prototype.slice.
+
+## Create a pipe function given below
+
+```js
+pipe(getName, uppercase, reverse)({ name: "Abhishek" }); // 'KEHSIHBA'
+```
+
+```js
+function getName(input) {
+  return input.name;
+}
+
+function uppercase(input) {
+  return input.toUpperCase();
+}
+
+function reverse(input) {
+  return input.split("").reverse().join("");
+}
+```

docs/closures.md

@@ -162,3 +162,27 @@ function log() {
   console.log(message);
 }
 ```
+
+## Explain the output
+
+```js
+function outer() {
+  let counter = 0;
+  return function inner() {
+    return counter++;
+  };
+}
+
+const bar = outer();
+console.log(bar());
+console.log(bar());
+
+const baz = outer();
+console.log(baz());
+console.log(baz());
+
+// 0
+// 1
+// 0
+// 1
+```

docs/prototypes.md

@@ -17,3 +17,16 @@ if (!Object.create) {
 ```
 
 This usage of Object.create(..) is by far the most common usage, because it's the part that can be polyfilled. There's an additional; set of functionality that the standard ES5 built-in Object.create(..) provides, which is not polyfillable for pre-ES5. As such, this capability is far less commonly used.
+
+## Create a speak() given below
+
+```js
+const name = "Abhishek";
+name.speak(); // "Abhishek can speak"
+```
+
+```js
+String.prototype.speak = function () {
+  return `${this} can speak`;
+};
+```