How can I remove characters from a string given in an array

Question

for self development purposes I want to create a function with two parameters - string and an array. It should return a string without the letters given in the array.

function filterLetters(str, lettersToRemove) {

}

const str = filterLetters('Achievement unlocked', ['a', 'e']);

Could someone give me any pointers on how to achieve this?

Does this answer your question? [How can I remove a character from a string using JavaScript?](https://stackoverflow.com/questions/9932957/how-can-i-remove-a-character-from-a-string-using-javascript) — kmoser, May 24 '22 at 06:13
Do you want the capital `A` removed too, or is it just lowercase letters you're asking about? — Andy, May 24 '22 at 06:15

kmoser · Accepted Answer · 2022-05-24T16:51:03.857

1

For each letter to be replaced, remove it (i.e. replace it with ''). When done, return the updated string:

function filterLetters(str, lettersToRemove) {
    lettersToRemove.forEach(function(letter){
        str = str.replaceAll(letter, '');
    })
    return str
}

Also see How to replace all occurrences of a string in JavaScript.

edited May 24 '22 at 16:51

answered May 24 '22 at 06:20

kmoser

8,780
3
24
40

Rahul Sharma · Answer 2 · 2022-05-24T06:36:46.130

You can use regex with replaceAll to remove all char from the string.

If you want to consider upper case also then use 'gi' else no need for regex also. str.replaceAll(char, '')

const removeChar = (str, c) => str.replaceAll(new RegExp(`[${c}]`, "gi"), "");

const run = () => {
  const str = "Achievement unlocked";
  const chars = ["a", "e"];

  let result = str;
  chars.forEach((char) => {
    result = removeChar(result, char);
  });
  return result;
};

console.log(run());

Timothy Vermeersch · Answer 3 · 2022-05-24T06:26:25.190

0

One easy way to do this would be to just loop over each value in the array and call the replace string method on str with each indices character. The code below does this.

function filterLetters(str, lettersToRemove){
   for (const letter of lettersToRemove){
      str = str.replaceAll(letter,"");
   }
   return str;
}

edited May 24 '22 at 06:26

answered May 24 '22 at 06:24

Timothy Vermeersch

1
1

Andy · Answer 4 · 2022-05-24T06:33:09.857

Create a regular expression by joining the array elements with a | (so a|e), and then use replaceAll to match those letters and replace them with an empty string.

If you want both upper- and lower-case letters removed add the "case-insenstive" flag to the regex. 'gi' rather than 'g'.

function filterLetters(str, lettersToRemove) {
  const re = new RegExp(lettersToRemove.join('|'), 'g');
  return str.replaceAll(re, '');
}

const str = filterLetters('Achievement unlocked', ['a', 'e']);

console.log(str);

score 0 · Answer 5 · answered May 24 '22 at 06:29

You should just transform the string into array by using split function and loop over that array and check if each character exist in the second argument of your function. To make this function not case sensitive I use toLowerCase to convert character to

function filterLetters(str, lettersToRemove) {
  return str.split('').reduce((acc, current)=> {
    if(lettersToRemove.indexOf(current.toLowerCase()) == -1){
      acc.push(current);
    }
    return acc;
  }, []).join('');
}

const str = filterLetters('Achievement unlocked', ['a', 'e']);

console.log(str);

How can I remove characters from a string given in an array

5 Answers5