visibilityOfElementLocated Vs visibilityOf
but the same way if i use "visibilityOf",it gives me NoSuchElementException
Actually, you are getting Exception by this line of code dr.findElement(By.linkText("Element3")), in your provided code this line will execute first and if element will be find then ExpectedConditions.visibilityOf() callable will execute.
FYI, WebDriver.findElement() either throws exception or returns a WebElement.
visibilityOfElementLocated Vs visibilityOf :-
visibilityOfElementLocatedis used for checking that an element is present on the DOM of a page and visible. Means it usesByobject instead ofWebElementobject with callable function to find that element first then check that element is visible or not.visibilityOfis used for checking that an element, known to be present on the DOM of a page, is visible. Means you have already found that element and just check only for that visibility.
According to this:
visibilityOf: Does not check for presence of the element as the error explains it.
visibilityOfElementLocated: Checks to see if the element is present and also visible. To check visibility, it makes sure that the element has a height and width greater than 0.