通过json数组获取菜单树html

function createTree(jsons,pid){
var ul = "";
ul = '<ul>' ;
for(var i = 0; i < jsons.length; i++){
if(jsons[i].pid == pid){
ul += '<li>' + jsons[i].name + "</li>" ;
ul += createTree(jsons, jsons[i].id) ;
}
}
ul += "</ul>" ;
return ul;
}