js给元素添加删除样式_js检查是否存在某个class

js添加classname_原生js添加classname_js中添加classname

是否存在某个class

function hasClass(node,classname){
  return node.className.match(new RegExp('(\s|^)'+cls+'(\s|$)'));
}

对节点增加class

function addClass(node,classname){
  if(!this.hasClass(node,classname)){
    node.className = (node.className+" "+classname).replace(/^s+|s+$/g,'');
  }
}

对节点删除class

function removeClass(node,classname){
  node.className = (node.className.replace(classname,"")).replace(/^s+|s+$/g,'');
}