javascript实现checkbox全选的代码

function checkall(checkNames){
  var allBoxs = document.getElementsByName(checkNames);
  for(var i = 0 ;i<allBoxs.length;i++){
    if(allBoxs[i].type == 'checkbox'){
      if(allBoxs[i].checked==false){
        allBoxs[i].checked = true ;
      }else{
        allBoxs[i].checked = false ;
      }
    }
  }
}

<a href="" id="checkAll">全选</a>
<script>
document.getElementById('checkAll').onclick = function () {
  checkall('goods')
};
</script>