function reverseLongWords(str){
//将字符串分割成单词数组
let words = str.split(' ');
//循环迭代单词数组
words.forEach((word, index) => {
//如果单词长度大于等于5
if(word.length >= 5){
//翻转单词
words[index] = word.split('').reverse().join('');
}
});
//返回处理后的字符串
return words.join(' ');
}
//示例
console.log(reverseLongWords('Hello world, this is a test case')); //olleH dlrow, this is a tset case