计算查询的字符串（带边界）在字符串出现的次数

java版

public static Integer countKey(String k, String html) {
        String[] words = html.split("\\b" + k + "\\b");
        return words.length - 1;
    }

nodejs版

function countKey(k, html) {
    var words = html.split(k);
    return words.length - 1;
}