全选按钮，点击全选，复选框全部选中

Posted 2021-03-01 niushuangmeng

  var box = document.getElementById("boxid");
  var loves = document.getElementsByClassName("sel");
      if(box.checked == false){//如果全选按钮不为选中
         for (var i = 0; i < loves.length; i++) {
             loves[i].checked = false;//将所有复选框设置为不选中
              }
      }else{
         for (var i = 0; i < loves.length; i++) {//否则将所有复选框设置为选中
             loves[i].checked = true;
              }
       }