JavaScript 配列内で最も頻繁に出現する要素を見つける方法

['pear', 'apple', 'orange', 'apple']

function mode(array) {
    // If the array is empty, return null
    if (array.length === 0) {
        return null;
    }

    // Create a map to store element counts
    var modeMap = {};

    // Initialize the maximum count and element
    var maxCount = 1;
    var maxEl = array[0];

    // Iterate through the array
    for (var i = 0; i < array.length; i++) {
        var el = array[i];

        // Check if the element is already in the map
        if (modeMap[el] === undefined) {
            modeMap[el] = 1;
        } else {
            // Increment the count if the element is already present
            modeMap[el]++;
        }
        // Update the maximum element and count if the current element's count is higher
        if (modeMap[el] > maxCount) {
            maxEl = el;
            maxCount = modeMap[el];
        }
    }
    // Return the element with the highest occurrence
    return maxEl;
}