Add es2017 code samples

Author: sudheerj

README.md

@@ -1331,10 +1331,10 @@ Each proposal for an ECMAScript feature goes through the following maturity stag
    ```
    But if the function parameter definition or function call only contains a comma, a syntax error will be thrown
    ```js
-   function func(,) {  // SyntaxError: missing formal parameter
+   function func1(,) {  // SyntaxError: missing formal parameter
      console.log('no args');
    };
-   func(,); // SyntaxError: expected expression, got ','
+   func1(,); // SyntaxError: expected expression, got ','
    ```
 
    **Note:** Trailing commas are not allowed in Rest Parameters and JSON.

es2017/5.string-padding.js

@@ -0,0 +1,15 @@
+// Pad start
+const cardNumber = '01234567891234';
+const lastFourDigits = cardNumber.slice(-4);
+const maskedCardNumber = lastFourDigits.padStart(cardNumber.length, '*');
+console.log(maskedCardNumber); // expected output: "**********1234"
+
+// Pad End
+const label1 = "Name";
+const label2 = "Phone Number";
+const value1 = "John"
+const value2 = "(222)-333-3456";
+
+console.log((label1 + ': ').padEnd(20, ' ') + value1);
+console.log(label2 + ": " + value2); // Name:                John
+                                     // Phone Number: (222)-333-3456

es2017/6.shared-memory-atomics.js

@@ -0,0 +1,39 @@
+// Atomic operations
+const sharedMemory = new SharedArrayBuffer(1024);
+const sharedArray = new Uint8Array(sharedMemory);
+sharedArray[0] = 10;
+
+Atomics.add(sharedArray, 0, 20);
+console.log(Atomics.load(sharedArray, 0)); // 30
+
+Atomics.sub(sharedArray, 0, 10);
+console.log(Atomics.load(sharedArray, 0)); // 20
+
+Atomics.and(sharedArray, 0, 5);
+console.log(Atomics.load(sharedArray, 0));  // 4
+
+Atomics.or(sharedArray, 0, 1);
+console.log(Atomics.load(sharedArray, 0));  // 5
+
+Atomics.xor(sharedArray, 0, 1);
+console.log(Atomics.load(sharedArray, 0)); // 4
+
+Atomics.store(sharedArray, 0, 10); // 10
+
+Atomics.compareExchange(sharedArray, 0, 5, 10);
+console.log(Atomics.load(sharedArray, 0)); // 10
+
+Atomics.exchange(sharedArray, 0, 10);
+console.log(Atomics.load(sharedArray, 0)); //10
+
+Atomics.isLockFree(1); // true
+
+// waiting to be notified
+const sharedMemory = new SharedArrayBuffer(1024);
+const sharedArray = new Int32Array(sharedMemory);
+
+Atomics.wait(sharedArray, 0, 10);
+console.log(sharedArray[0]); // 100
+
+Atomics.store(sharedArray, 0, 100);
+Atomics.notify(sharedArray, 0, 1);

es2017/7.trailing-commas.js

@@ -0,0 +1,11 @@
+// Params include trailing comma
+function func(a,b,) { // declaration
+    console.log(a, b);
+}
+func(1,2,); // invocation
+
+// function call only contains a comma
+function func1(,) {  // SyntaxError: missing formal parameter
+    console.log('no args');
+};
+func1(,); // SyntaxError: expected expression, got ','