Add simple examples

tshemsedinov · tshemsedinov · commit 5be5a0a0a831 · 2019-04-28T17:43:52.000+03:00
diff --git a/JavaScript/1-function.js b/JavaScript/1-function.js
@@ -0,0 +1,28 @@
+'use strict';
+
+const randomChar = () => String
+  .fromCharCode(Math.floor((Math.random() * 25) + 97));
+
+const subscribe = observer => {
+  const observable = { observer };
+  const timer = setInterval(() => {
+    const char = randomChar();
+    observer(char);
+  }, 200);
+  observable.complete = () => clearInterval(timer);
+  return observable;
+};
+
+// Usage
+
+let count = 0;
+const observable = subscribe(observer);
+
+function observer(char) {
+  process.stdout.write(char);
+  count++;
+  if (count > 50) {
+    observable.complete();
+    process.stdout.write('\n');
+  }
+}
diff --git a/JavaScript/2-class.js b/JavaScript/2-class.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const randomChar = () => String
+  .fromCharCode(Math.floor((Math.random() * 25) + 97));
+
+class Observable {
+  constructor() {
+    this.timer = setInterval(() => {
+      if (!this.onData) return;
+      const char = randomChar();
+      this.onData(char);
+    }, 200);
+  }
+  subscribe(onData) {
+    this.onData = onData;
+    return this;
+  }
+  complete() {
+    clearInterval(this.timer);
+  }
+}
+
+// Usage
+
+let count = 0;
+const observable = new Observable().subscribe(char => {
+  process.stdout.write(char);
+  count++;
+  if (count > 50) {
+    observable.complete();
+    process.stdout.write('\n');
+  }
+});
