如何使用“\w+”在字符串中查找单词？

Question

I need to write a function that takes a string as input. This function will return a List[String]. I have to use the regular expression "\w+" in this function as a requirement for this task. So when given a line string of random text with a few actual words dotted around inside it, I need to add all of these 'proper' words and add them to the list to be returned. I must also use ".findAllIn". I have tried the following

def foo(stringIn: String) : List[String] = {
    val regEx = """\w+""".r
    val match = regEx.findAllIn(s).toList
    match
}

But it just returns the string that I pass into the function.

Answer 1

match is a reserved keyword in scala. So you just need to replace that.

def foo(stringIn: String) : List[String] = {
    val regEx = """\w+""".r
    regEx.findAllIn(stringIn).toList
}

scala> foo("hey. how are you?")
res17: List[String] = List(hey, how, are, you)

\\w is the pattern for a word character, in the current regex context equal to [a-zA-Z_0-9] , that matches a lower- and uppercase letters, digits and an underscore.

\\w+ is for one ore more occurrences of the above.

scala> foo("hey")
res18: List[String] = List(hey)

In above case, there is nothing for the regex to split by. Hence returns the original string.

scala> foo("hey-hey")
res20: List[String] = List(hey, hey)

- is not part of \\w . Hence it splits by -