Javascript explained:
findLast() and findLastIndexOf() array methods!
findLast() and findLastIndexOf() array methods!
The findLast and findLastIndexOf methods are used to search an array for the first element that satisfies a specific condition & return its value or index, respectively.
In this thread, we'll discuss these methods in more detail, code examples and their use cases.
In this thread, we'll discuss these methods in more detail, code examples and their use cases.
👉 The .findLast() method returns the last element in an array that matches the given criteria.
It searches the array from the end to the beginning, unlike the .find() method that searches from the beginning to the end.
It searches the array from the end to the beginning, unlike the .find() method that searches from the beginning to the end.
👉 The .findLastIndex() method returns the index of the last element in an array that matches the given criteria.
👉 Both methods take a callback function that tests each element in the array.
👉 Both methods take a callback function that tests each element in the array.
The callback function returns true if the element matches the given criteria & false otherwise.
👉 Here's an example of how to use the .findLast() method to find the last even number in an array:
👉 Here's an example of how to use the .findLast() method to find the last even number in an array:
👉 Similarly, here's an example of how to use the .findLastIndexOf() method to find the index of the last even number in an array:
👉 Note that both methods return undefined or -1 if there is no match found in the array.
👉 The .findLast() and .findLastIndexOf() methods can be useful when you need to search for a specific item in an array and want to start from the end instead of the beginning.
👉 The .findLast() and .findLastIndexOf() methods can be useful when you need to search for a specific item in an array and want to start from the end instead of the beginning.
Here are a few use cases of the findLast method:
- A news app that displays a list of articles with the most recent articles at the top of the page.
💡 The findLast method can be used to quickly find the most recent article in the list based on its date and time stamp.
- A news app that displays a list of articles with the most recent articles at the top of the page.
💡 The findLast method can be used to quickly find the most recent article in the list based on its date and time stamp.
- An e-commerce website that displays a list of products on a category page.
💡 The findLast method can be used to find the most expensive product in the list and display it at the top of the page.
💡 The findLast method can be used to find the most expensive product in the list and display it at the top of the page.
- A social media app that displays a list of friends with the most recently added friends at the top.
💡 The findLast method can be used to quickly find the most recently added friend in the list.
💡 The findLast method can be used to quickly find the most recently added friend in the list.
Similarly, here are a few use cases for the findLastIndexOf method:
- A music app that allows users to create playlists.
💡 The findLastIndexOf method can be used to find the index of the last song in a playlist and play it.
- A music app that allows users to create playlists.
💡 The findLastIndexOf method can be used to find the index of the last song in a playlist and play it.
- A calendar app that allows users to schedule events.
💡 The findLastIndexOf method can be used to find the index of the last event in a day and display it at the top of the calendar.
💡 The findLastIndexOf method can be used to find the index of the last event in a day and display it at the top of the calendar.
- A weather app that displays the daily temperature readings for a location.
💡 The findLastIndexOf method can be used to find the index of the last temperature reading of the day and display it as the high temperature for the day.
💡 The findLastIndexOf method can be used to find the index of the last temperature reading of the day and display it as the high temperature for the day.
As a parting note, you can look at some of my other threads on array methods here:
That's a wrap!
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Hey, I write two threads every day on web dev and it takes a lot of time and effort.
So, I'd be glad if you could spare me a minute to:
✅ Follow me @sumitsaurabh927 for more of these.
✅ RT the tweet below to show me some love.
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