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javascriptregexfunctional-programming

Regular Expression | Apply Functional Programming to Convert Strings to URL Slugs

Question

Fill in the urlSlug function so it converts a string title and returns the hyphenated version for the URL. You can use any of the methods covered in this section, and don't use replace. Here are the requirements:

The input is a string with spaces and title-cased words

The output is a string with the spaces between words replaced by a hyphen (-)

The output should be all lower-cased letters

The output should not have any spaces.

My Solution

var globalTitle = " Winter Is  Coming";


function urlSlug(title) {
  let regex = /(?<!\s)\s(?!\s)/g
  
  let a = title
  .toLowerCase()
  .trim()
  .split(regex)
  .join('-')
  return a;
}


console.log(urlSlug(globalTitle))

My Question

I want to use positive and negative look aheads / look behinds to resolve this problem: my particular issue seems to be if the string has more than one space. What changes can be made to make this work?

Solution

  • You can use quantifier + which means one or more

    var globalTitle = " Winter Is  Coming";


function urlSlug(title) {
  let regex = /\s+/g
  
  let a = title
  .toLowerCase()
  .trim()
  .split(regex)
  .join('-')
  return a;
}


console.log(urlSlug(globalTitle))