RxJS Demos
.startWith
by dream apple
HTML
<div class="app">
<button id="test">test</button>
</div>
<script src="https://cdn.bootcss.com/rxjs/5.0.0-rc.1/Rx.min.js"></script>
JavaScript
let testEle = document.querySelector('#test');
let test = Rx.Observable.fromEvent(testEle, 'click');
test.startWith('startup click')
.subscribe((e) => {
console.log(e);
});