iife and closure

Author: ashfaq

closures.js

@@ -0,0 +1,77 @@
+function greet(whatToSay){
+  return function(name){
+    console.log(`${whatToSay} : ${name}`)
+  }
+}
+
+greet('Hi')('ashfaq');
+
+var sayHi = greet('Hi');
+// function have access to the variable{whatToSay} of outer scope event it is invoked outside of the scope{execution context}
+
+sayHi("Kranthi");
+
+
+
+
+function build(){
+  var arr= [];
+  for(var i=0; i<3; i++){
+    arr.push(
+      function(){
+        console.log(i)
+      }
+    )
+  }
+  return arr;
+}
+
+var fs = build();
+
+fs[0]();  //3
+fs[1]();  //3
+fs[2]();  //3
+
+
+// solution1 Old school By using IIFE 
+function build2(){
+  var arr= [];
+  for(var i=0; i<3; i++){
+    arr.push(
+      (function(j){
+        return function(){
+          console.log(j)
+        }
+      }(i))  
+    )
+  }
+  return arr;
+}
+
+var fs2 = build2();
+
+fs2[0]();  //3
+fs2[1]();  //3
+fs2[2]();  //3
+
+
+// ES6 solution By using let 
+
+
+function build3(){
+  var arr = [];
+  for(let i=0; i<3; i++){
+    arr.push(
+      function(){
+        console.log(i)
+      }
+    )
+  }
+  return arr;
+}
+
+var fs3 = build3();
+
+fs3[0]();  //3
+fs3[1]();  //3
+fs3[2]();  //3

iife.js

@@ -0,0 +1,31 @@
+// Function declaration or Function statement
+function greet(name){
+  console.log(`Hello ${name}`);
+}
+greet('ashfaq')
+
+
+
+// Function Expression { function is created on the fly}  
+// Expression Returns something
+var greetName = function(name){
+  console.log(`Hello ${name}`);
+};
+
+greetName('ansari');
+
+// IIFE Immediately invoking function expression 
+//VERSION 1
+(function(name){
+  console.log(`Hello ${name}`);
+}('Walter'));
+
+//VERSION 2
+
+(function(name){
+  console.log(`Hello ${name}`);
+})('Walter');
+
+
+
+

index.html

@@ -6,6 +6,6 @@
         <meta charset="utf-8"/>
 
         <!-- <script src="collection.js"></script> -->
-        <script src="semiColonInjection.js"></script>
+        <script src="closures.js"></script>
     </body>
 </html>

semiColonInjection.js

@@ -1,5 +1,5 @@
 function returnsNothing(){
-  return                     //Automatic Semicolon (;) will be injected By syntax Parser.
+  return        //Automatic Semicolon (;) will be injected By syntax Parser.
   {
     key: 'value'
   }