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In this guide, we look at the most common use case of querySelector and getElementById. We also compare these two methods and walk you through a basic example of how each of them work.
What is querySelector?
querySelectorAll () which selects all elements that match a particular DOM selector.
These two methods are incredibly versatile. This is because the CSS selector syntax allows you to select an element from a web page.
Using querySelector, you don’t have to worry about being limited by the ability to select items only for the or ID class , as you would if you used getElementById or getElementsByClassName. These methods are especially useful if the elements you select are similar to those you select in your CSS stylesheet.
We have defined a paragraph of text with the name of the class "accessibility". Then we select that paragraph using the
This code selects the first element whose class is equal to " accessibility". The "." means that we want to select a class. If we had two elements with the class "accessibility", we could use the
querySelectorAll () to retrieve them both
What is getElementById?
getElementById () method gets an element based on its attribute ID, hence the name.
This method is more restrictive than querySelector because you cannot retrieve items based on their particular ID.
Use this option if you want to retrieve a single element from the web page. indeed, HTML ID must be unique for a particular element. You can not use a card of identity to refer to two elements on the Web page.
we will retrieve an element using the getElementById selector. First, we will write the HTML code from which we will choose an element:
The obvious similarity between these two methods is that the two elements of selecting a web page. They do it in different ways.
With a querySelector declaration, you can select an element based on a CSS selector. This means that you can select items by ID, class, or any other type of selector. Using the getElementById method, you cannot select an element based on its ID.
As a general rule, you should go for the selector that does the job most clearly.
If you just need to select an element by ID or class, you can use getElementById or getElementsByClassName, respectively. If you need to use a more elaborate rule to select items, the querySelector method is the best option
The querySelector method allows you to retrieve an element using a CSS select query . The getElementById method retrieves an element by its DOM ID.
Both methods have broad browser support. You should choose to use querySelector if you need to select items using more complex rules that are easily representable using a CSS selector. If you want to select an element based on its ID, using getElementById is a good choice.
Now that you have the knowledge to know when to use the querySelector and getElementByID methods like a pro!
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I would like to know how to put a time delay in a Python script.
time.sleep(5) # Delays for 5 seconds. You can also use a float value.
Here is another example where something is run approximately once a minute:
print("This prints once a minute.")
time.sleep(60) # Delay for 1 minute (60 seconds).
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How do I delete a file or folder in Python?
Path objects from the Python 3.4+
pathlib module also expose these instance methods:
Want to excel in Python? See our review of the best Python online courses 2022. If you are interested in Data Science, check also how to learn programming in R.
By the way, this material is also available in other languages:
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