leetcode/work/1/Easy/Hash Table/1832.check-if-the-sentence-is-pangram.js

/*
 * 1832. Check if the Sentence Is Pangram
 * Difficulty: Easy
 * https://leetcode.com/problems/check-if-the-sentence-is-pangram/
 * 
 * ──────────────────────────────────────────────────
 * 
 * A pangram is a sentence where every letter of the English alphabet
 * appears at least once.
 * 
 * Given a string sentence containing only lowercase English letters,
 * return true if sentence is a pangram, or false otherwise.
 * 
 *  
 * 
 * Example 1:
 * 
 * Input: sentence = "thequickbrownfoxjumpsoverthelazydog"
 * Output: true
 * Explanation: sentence contains at least one of every letter of the
 * English alphabet.
 * 
 * Example 2:
 * 
 * Input: sentence = "leetcode"
 * Output: false
 * 
 *  
 * 
 * Constraints:
 * 
 * 	• 1 <= sentence.length <= 1000
 * 
 * 	• sentence consists of lowercase English letters.
*/

/**
 * @param {string} sentence
 * @return {boolean}
 */
var checkIfPangram = function(sentence) {
    const freq = {};
    for (let c of sentence) freq[c] = (freq[c] || 0) + 1;
    
    if (Object.keys(freq).length === 26){
        return true;
    }
    return false;
};