How do I split a string by whitespace and ignoring leading and trailing whitespace into an array of words using a regular expression?
JavascriptRegexStringWhitespaceRemoving WhitespaceJavascript Problem Overview
I typically use the following code in JavaScript to split a string by whitespace.
"The quick brown fox jumps over the lazy dog.".split(/\s+/);
// ["The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog."]
This of course works even when there are multiple whitespace characters between words.
"The quick brown fox jumps over the lazy dog.".split(/\s+/);
// ["The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog."]
The problem is when I have a string that has leading or trailing whitespace in which case the resulting array of strings will include an empty character at the beginning and/or end of the array.
" The quick brown fox jumps over the lazy dog. ".split(/\s+/);
// ["", "The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog.", ""]
It's a trivial task to eliminate such empty characters, but I'd rather take care of this within the regular expression if that's at all possible. Does anybody know what regular expression I could use to accomplish this goal?
Javascript Solutions
Solution 1 - Javascript
If you are more interested in the bits that are not whitespace, you can match the non-whitespace instead of splitting on whitespace.
" The quick brown fox jumps over the lazy dog. ".match(/\S+/g);
Note that the following returns null
:
" ".match(/\S+/g)
So the best pattern to learn is:
str.match(/\S+/g) || []
Solution 2 - Javascript
" The quick brown fox jumps over the lazy dog. ".trim().split(/\s+/);
Solution 3 - Javascript
Instead of splitting at whitespace sequences, you could match any non-whitespace sequences:
" The quick brown fox jumps over the lazy dog. ".match(/\S+/g)
Solution 4 - Javascript
Not elegant as others code but very easy to understand:
countWords(valOf)
{
newArr[];
let str = valOf;
let arr = str.split(" ");
for (let index = 0; index < arr.length; index++)
{
const element = arr[index];
if(element)
{
newArr.push(element);
}
}
const NumberOfWords = newArr.length;
return NumberOfWords;
}