Execute Javascript in Selenium WebDriver

To execute Javascript using Selenium WebDriver, we can use JavascriptExecutor interface to implement it. There are two methods in JavascriptExecutor interface.

• executeScript(String, Object...)
• executeAsyncScript(String, Object...)

Here is a simple test,

    @Test
    public void testJavascript() throws InterruptedException {
        // wait 10 seconds if web element is not present
        driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
        JavascriptExecutor jsExecutor = (JavascriptExecutor) driver;
        jsExecutor.executeScript("alert('hello world');");
        TimeUnit.SECONDS.sleep(4);
        driver.switchTo().alert().accept();

        WebElement continents = (WebElement) jsExecutor
            .executeScript("return document.getElementById('continents')");
        assertNotNull(continents);

        String selectedContinent = jsExecutor
             .executeScript("return document.getElementById('continents').value")
             .toString();
        assertEquals("Asia", selectedContinent);
    }