String comparison to the number of matching symbols.

is-anagram.js

let isAnagram = (str1, str2) => {
        if (str1.length !== str2.length) return console.log('false');

        let obj1 = {},
            obj2 = {},
            equal = str1.length;
            
        for (let i = 0; i < str1.length; i++) {
            (obj1[str1.charAt(i)]) ? obj1[str1.charAt(i)] += 1 : obj1[str1.charAt(i)] = 1;
            (obj2[str2.charAt(i)]) ? obj2[str2.charAt(i)] += 1 : obj2[str2.charAt(i)] = 1;
        }
        
        for (let key in obj1) {
            if (key in obj2 && obj1[key] === obj2[key]) equal -= 1;
        }
        
        (equal == 1) ? console.log('true') : console.log('false');
    };
    
    isAnagram('aab', 'bba'); // false
    isAnagram('aab', 'aba') // true
    isAnagram('aab', 'aab') // true
    isAnagram('aab', 'aaba') // false