how to check the whitespace in string and convert it into array - Javascript

Question

var convertToArray = (txt) => {
  let arr = txt.split(" ");
  console.log(arr);
};

convertToArray("Hello World   ");

At the end of Hello World I have 4 spaces and now I need to take that whitespace as element of an array.

E.g.: ["Hello", "World", " "]

Answer 1

Use String.match instead of split and filter out the single spaces. Something like:

const convertToArray = (txt) => {
  return txt.match(/\s{1,}|\b(.+?)\b/g)?.filter(v => v !== ` `);
};

console.log(JSON.stringify(convertToArray("Hello World   ")));
console.log(JSON.stringify(convertToArray("   Hello World   and bye again   ")));

Note: the above will only work for words within word boundaries (letters (A–Z, a–z), numbers (0–9), and underscore (_)). When all characters in words should be included (like in "Hello World! "), feel free to use this parsing function:

console.log(
  JSON.stringify(parseWords(`Hello World!    `)));
console.log(
  JSON.stringify(parseWords(`Hello World! And    well... bye again!   `)));
// including single spaces
console.log(
  JSON.stringify(parseWords(`Hello World! And    well... bye again!   `, 1)));

function parseWords(txt, includeSingleSpaces = false) {
  let result = [txt[0]];
  txt = txt.slice(1).split('');
  
  while (txt.length) {
    const last = result[result.length - 1].at(-1);
    
    if (txt[0] === ` ` && last === ` ` || txt[0] !== ` ` && last !== ` `) {
      result[result.length - 1] += txt.shift();
      continue;
    }

    if (last !== ` ` && txt[0] === ` ` || last === ` ` && txt[0] !== ` `) {
      result.push(txt.shift());
      continue;
    }

    result[result.length - 1] += txt.shift();
    result.push(txt.shift());
  }
  
  return includeSingleSpaces ? result : result.filter(v => v !== ` `);
}