Interview Questions-Strings

				
					
//1. USING INCLUDES OF String
const test1 = (str) => {
  const strUpper = str.toUpperCase();
  for (let i = 65; i <= 90; i++) {
    if (!strUpper.includes(String.fromCharCode(i))) {
      return false;
    }
  }
  return true;
};

// String.fromCharCode(65); A
// String.fromCharCode(66); B
// String.fromCharCode(67); C
// String.fromCharCode(68); D
// String.fromCharCode(69); E
// String.fromCharCode(70); F
// String.fromCharCode(71); G

//////////////////////////////////////////////////////////
//2.USING ARRAY
const test2 = (str) => {
  str = str.toUpperCase();
  const array = new Array(26).fill(false);
  for (let i = 0; i < str.length; i++) {
    if (str[i] >= "A" && str[i] <= "Z") {
      let index = str.charCodeAt(i) - "A".charCodeAt(0);
      array[index] = true;
    }
  }
  let result = array.every((i) => i);
  return result;
};

//Explanation
/*
FIRST ITERATION
"A".charCodeAt(0) = 65
Lets assume the first letter is C
str.charCodeAt(i) = 67
67-65= 2
end position becomes true
[undefined,undefined,true, undefined .......]] //length is 26

SECOND ITERATION
/*"A".charCodeAt(0) = 65
Lets assume the second  letter is F
str.charCodeAt(i) = 70
70-65= 5

[undefined,undefined,true,undefined,true .......]]

*/
//////////////////////////////////////////////////////////
///3.USING MAP
const test3 = (str) => {
  str = str.toUpperCase();
  const alphabets = new Map();
  for (let i = 0; i < str.length; i++) {
    if (str[i] >= "A" && str[i] <= "Z") {
      alphabets.set(str[i], true);
    }
  }
  if (alphabets.size === 26) {
    return true;
  }
  return false;
};

/*Explanation

alphabets.set('A',true)
alphabets.set('A',true)
alphabets.set('A',true)
alphabets.set('B',true)

Map(2) {'A' => true, 'B' => true}

it will be only two values as keys cant be repeated
so check the count after th e loop ends. if it is 26 then its panagram
*/

//////////////////////////////////////////////////////////
///4.USING SET////
const test4 = (str) => {
  str = str.toUpperCase();
  const alphabets = new Set();
  for (let i = 0; i < str.length; i++) {
    if (str[i] >= "A" && str[i] <= "Z") {
      alphabets.add(str[i], true);
    }
  }
  if (alphabets.size === 26) {
    return true;
  }
  return false;
};

console.log(test1("TThe quick /// browns fox jump over the lazy dog"));
console.log(test2("TThe quick ,... browns fox jump over the lazy dog"));
console.log(test3("TThe quick ADD@ browns fox jump over the lazy dog"));
console.log(test4("TThe quick ADD@ browns fox jump over the lazy dog"));