菜单树，序列化菜单

之前遇到的一些题目，在这写下来，方便查看

生成菜单树

<script>
var arr = [
    {name:'学习',id: '0',parentId:null},
    {name:'看书',id: '1',parentId:'0'},
    {name:'做题',id: '2',parentId:'0'},
    {name:'苏菲的世界',id: '3',parentId:'1'},
    {name:'高数',id: '4',parentId:'2'},
    {name:'英语',id: '5',parentId:'2'}
    ];
    var firstMenu = "<ul>",
    len = arr.length;
    function tree(arr){
    for(let i=0;i<len;i++){
        if(arr[i].parentId == null){
            firstMenu += "<li>"+arr[i].name;
            second(arr, arr[i]);
        }
    }
    firstMenu += "</li></ul>";
    $(".tree").append($(firstMenu));
    }
    function second(arr, father){
    let isFirst = true,
        sec = " ";
    for(let i=0;i<len;i++){
        if(arr[i].parentId == father.id){
            if(sec == " "){
                sec = "<ul>"
                firstMenu += sec;
            };
            sec = "<li>"+arr[i].name;
            firstMenu += sec;
            second(arr, arr[i]);
        }
    }
    if(sec != " ") firstMenu+="</ul></li>";
    }
    $(function(){ tree(arr); });
</script>

序列化菜单

<script>
function serialize(form){
    var parts=[],
    field=null,
    i;
    for(i=0;i<form.elements.length;i++){
        field=form.elements[i];
        switch(field.type){
            case "submit":
            case "button":
            case "reset":
                break;
            case "radio":
            default:
                if(field.name.length){
                    parts.push(encodeURIComponent(field.name)+"="+encodeURIComponent(field.value));
                }
        }
    }
    return parts;
}
</script>

想要得到“？”后某个参数的值，可以写代码

<script>
function GetQueryString(name){
    var reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
    var r = window.location.search.substr(1).match(reg);
    if(r!=null){
       return decodeURIComponent(r[2]);
    }else{
       return null;
    } 
 }
 document.write("name = "+ GetQueryString("name")+"<br />");
 document.write("age ="+ GetQueryString("age"));
</script>