Question

How to find missing alphabet characters from a string in TypeScript

Answer 1

function getMissingAlphabetChars(input: string): string[] {
  const present = new Set<string>();

  // Normalize: lowercase + keep only a–z
  for (const ch of input.toLowerCase()) {
    if (ch >= "a" && ch <= "z") {
      present.add(ch);
    }
  }

  // Collect missing letters
  const missing: string[] = [];
  for (let code = 97; code <= 122; code++) { // 'a'..'z'
    const letter = String.fromCharCode(code);
    if (!present.has(letter)) {
      missing.push(letter);
    }
  }

  return missing;
}

const missing = getMissingAlphabetChars("TypeScript Programming");
console.log(missing);




/*
run:

["b", "d", "f", "h", "j", "k", "l", "q", "u", "v", "w", "x", "z"] 

*/

 

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