a simple function for check that is pangram text or not

checkPangram1.js

function isPangram(sentence)
{
    const setSentence = new Set(sentence.toLowerCase().replace(/[^a-z]/g,""));
    return setSentence.size === 26;
}

const pangram = "The quick brown fox jumps over the crazy little dog";
alert(isPangram(pangram)); //true

checkPangram2.js

const isPangram = (name) => {
	return 'abcdefghijklmnopqrstuvwxyz'.split('').every(alphabet => name.toLowerCase().includes(alphabet));
}

let text = "The quick brown fox jumps over the crazy little dog";
alert(isPangram(text)); //true

checkPangram3.js

let string = '!The quick brown fox jumps over the?lazy-dog.';

function isPangram(str) {
  if (!str) return;
  
  let res = str.toLowerCase()
               .replace(/[^a-z]/g, '')
               .split('')
               .filter((val, id, self) => {
                  return self.indexOf(val) === id;
               });
  
  return res.length === 26;
}

alert(isPangram(string)); //true