Anagrams

Check if strings are equal by symbols inside (order doesn't matter)

function isAnagrams(str1, str2) {
    if (!str1 && !str2) return true
    if (str1.length !== str2.length) return false

    const getFrequencyObject = (arr) => {
        return arr.reduce((acc, value) => {
            acc[value] = acc[value] ? ++acc[value] : 1
            return acc
        }, {})
    }

    const frequencyStr1 = getFrequencyObject([...str1])
    const frequencyStr2 = getFrequencyObject([...str2])

    for (const key in frequencyStr1) {
        if (!(key in frequencyStr2) || frequencyStr1[key] !== frequencyStr2[key]) {
            return false
        }
    }
    return true
}

console.log(isAnagrams('cinema', 'iceman')) // true