JSONUtil.serialize(map)和JSON.toJSONString(map)的区别

 JSONUtil.serialize(map)和JSON.toJSONString(map)的区别

 

数据库查询出来的map有一个字段为空

 

通过System.out.println()输出

JSONUtil.serialize(map)： {"one":"1","two":"null","three":"3","four":"4","five":"5"}
JSON.toJSONString(map)： {"one":"1","three":"3","four":"4","five":"5"}

 

jsp页面

Js的eval()方法：

var jsonObj = eval("("+jsonStr+")");

//如果使用JSONUtil.serialize(map)可以输出空串，如果是JSON.toJSONString(map)会报错

jsonObj.two;

 

jquery-1.9.1.js的val()源码如下

val: function( value ) {
  var ret, hooks, isFunction,
   elem = this[0];

  if ( !arguments.length ) {
   if ( elem ) {
    hooks = jQuery.valHooks[ elem.type ] || jQuery.valHooks[ elem.nodeName.toLowerCase() ];

    if ( hooks && "get" in hooks && (ret = hooks.get( elem, "value" )) !== undefined ) {
     return ret;
    }

    ret = elem.value;

    return typeof ret === "string" ?
     // handle most common string cases
     ret.replace(rreturn, "") :
     // handle cases where value is null/undef or number
     ret == null ? "" : ret;
   }

   return;
  }