正则匹配结果不完整？

Question

<script>
str='<span style=".." name="bad_words">hello</span>  xxx xxx<span style=".." name="bad_words">how are you</span>';
re=/<span[^<]*name="bad_words">(.*?)<\/span>/ig;
alert(re.exec(str));//得到span</script>
后面how are you那个span 抓不到

Answer 1

<script> 
str=' <span style=".." name="bad_words">hello </span>  xxx xxx <span style=".." name="bad_words">how are you </span>'; 
re=/ <span[^>]*name="bad_words">.*?<\/span>/ig; 
while((result = re.exec(str)) != null){
alert(result[0])
}</script> 

Answer 2

<script>
var str=' <span style=".." name="bad_words">hello </span>  xxx xxx <span style=".." name="bad_words">how are you </span>';
 var rex=/(<span\s.*?\s?)name\s*=\s*"bad_words"(.*?>)/ig;
alert(str.match(rex));
</script>