JavaScript——t全选案例如下：
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>02.JavaScript——t全选</title><style type="text/css" media="screen">.box{width:120px;height:250px;border:1px solid #000;border-radius:5px;padding:5px 10px;margin:20px auto;}.box div{border-bottom:1px solid #ccc;padding-bottom:10px;margin-bottom:8px;}.box input{margin:8px;}</style><script type="text/javascript">function checkAll(){var checkall,item;checkall=document.getElementById('checkall');item=document.getElementsByName('item[]');for(var i=0;i<item.length;i++){if(checkall.checked){item[i].checked=true;}else{item[i].checked=false;}}}</script></head><body><div class="box"><div><input type="checkbox" id="checkall" onclick="checkAll(this)"><label for="checkall">全选</label></div><input type="checkbox" name="item[]">选项1<br><input type="checkbox" name="item[]">选项2<br><input type="checkbox" name="item[]">选项3<br><input type="checkbox" name="item[]">选项4<br><input type="checkbox" name="item[]">选项5<br><input type="checkbox" name="item[]">选项6<br></div></body></html>