Hello, and welcome! Are you ready to take your string manipulation skills to the next level? Today, we'll explore a task that enhances your understanding of strings and trains your ability to think creatively. The task at hand involves splitting a string into words and then reversing each word as if reflected in a mirror using Scala. Intrigued? Let's dive right in!

Consider a string filled with words. Your task is to write a Scala function that accepts such a string. It should then take each of those words, reverse their character order, and finally stitch them all together to form a new string with reversed words.

Here's what you need to keep in mind:

• The input string will contain between 1 and 100 words.
• Each word is a sequence of characters separated by white space.
• A word is composed of characters ranging from a to z, A to Z, 0 to 9, or even an underscore _.
• The given string will not start or end with a space, and double spaces will not appear either.
• After reversing the words, your program should return a single string with the words preserving their original order.

Example

Suppose the input string is "Hello neat scala_123".

The function will work on this in the following fashion:

• 'Hello' becomes 'olleH'
• 'neat' becomes 'taen'
• 'scala_123' becomes '321_alacs'

The function combines the obtained strings into one string, resulting in "olleH taen 321_alacs".

Therefore, if solution("Hello neat scala_123") is called, the returned value should be "olleH taen 321_alacs".

Let's start breaking this down!

Our first step requires us to separate the words in the sentence. Scala provides us with a split method, which breaks a given string at specified separators and outputs an array of words. If you want to split by space, you can use split(" "):

Scala
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1// an initial example string
2val inputStr = "Hello neat scala_123"
3
4// split the string into words
5val words = inputStr.split(" ")
6
7println(words.mkString(","))

You will see Hello,neat,scala_123 printed out, showing each word separated by a comma.

We've successfully extracted the words from the sentence, but they're not reversed yet. Scala provides a reverse method on strings to easily reverse their characters:

Scala
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1// an example string
2val inputStr = "Hello neat scala_123"
3
4// split the string into words
5val words = inputStr.split(" ")
6
7// reverse each word 
8val reversedWords = words.map(_.reverse)
9
10println(reversedWords.mkString(","))

Aha! Now you can see the reversed words: olleH,taen,321_alacs.

Finally, we need to bring these reversed words back together again into a single string with spaces as separators. We can use mkString(" ") to achieve this:

Scala
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1def solution(inputStr: String): String = {
2    // split the string into words
3    val words = inputStr.split(" ")
4
5    // reverse each word
6    val reversedWords = words.map(_.reverse)
7
8    // join the words back together with space as a separator
9    val result = reversedWords.mkString(" ")
10
11    result
12}
13
14// Now we call the function and print the returned result outside of the function
15println(solution("Hello neat scala_123"))  // this will print: 'olleH taen 321_alacs'

Well done! By completing this lesson, you've gained proficiency in manipulating strings using Scala, especially when it comes to reversing the order of characters in a word. I hope you're feeling more confident and enthusiastic about your Scala skills. Remember, the key to mastery is regular practice, so take a moment to explore related problems and practice what you’ve learned. It's all part of the joy of learning!