调试语句

JSON.parse(text [, reviver]) //字符串到js对象
JSON.stringify(value [, replacer] [, space]) //js对象到字符串

var a='{"k1":"v1","k2":"v2","k3":"v3"}'
var r=JSON.parse(a,function(key,value){console.log(key+' >> '+JSON.stringify(value));return value});
//k1 >> "v1"
//k2 >> "v2"
//k3 >> "v3"
// >> {"k1":"v1","k2":"v2","k3":"v3"}

var b={a:'qwe',b:'asd',c:'zxc'}
JSON.stringify(b,function(key,value){console.log(key+' >> '+value);return value;})
//>> [object Object]
//a >> qwe
//b >> asd
//c >> zxc
//"{"a":"qwe","b":"asd","c":"zxc"}"