如何将JavaScript对象转换为字符串?
例子:
var o = {a:1, b:2}
console.log(o)
console.log('Item: ' + o)
输出:
对象{a=1, b=2} //非常好的可读输出:) Item: [object object] //不知道里面有什么:(
如何将JavaScript对象转换为字符串?
例子:
var o = {a:1, b:2}
console.log(o)
console.log('Item: ' + o)
输出:
对象{a=1, b=2} //非常好的可读输出:) Item: [object object] //不知道里面有什么:(
当前回答
如果只是想查看用于调试的对象,可以使用
var o = {a:1, b:2}
console.dir(o)
其他回答
var o = {a:1, b:2};
o.toString=function(){
return 'a='+this.a+', b='+this.b;
};
console.log(o);
console.log('Item: ' + o);
因为Javascript v1.0可以在任何地方工作(甚至是IE) 这是一种本地方法,允许在调试和生产过程中对对象进行定制 https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/toString
有用的例子
var Ship=function(n,x,y){
this.name = n;
this.x = x;
this.y = y;
};
Ship.prototype.toString=function(){
return '"'+this.name+'" located at: x:'+this.x+' y:'+this.y;
};
alert([new Ship('Star Destroyer', 50.001, 53.201),
new Ship('Millennium Falcon', 123.987, 287.543),
new Ship('TIE fighter', 83.060, 102.523)].join('\n'));//now they can battle!
//"Star Destroyer" located at: x:50.001 y:53.201
//"Millennium Falcon" located at: x:123.987 y:287.543
//"TIE fighter" located at: x:83.06 y:102.523
还有,作为奖励
function ISO8601Date(){
return this.getFullYear()+'-'+(this.getMonth()+1)+'-'+this.getDate();
}
var d=new Date();
d.toString=ISO8601Date;//demonstrates altering native object behaviour
alert(d);
//IE6 Fri Jul 29 04:21:26 UTC+1200 2016
//FF&GC Fri Jul 29 2016 04:21:26 GMT+1200 (New Zealand Standard Time)
//d.toString=ISO8601Date; 2016-7-29
使用javascript String()函数
String(yourobject); //returns [object Object]
或stringify ()
JSON.stringify(yourobject)
当然,要将对象转换为字符串,你必须使用自己的方法,例如:
function objToString (obj) {
var str = '';
for (var p in obj) {
if (Object.prototype.hasOwnProperty.call(obj, p)) {
str += p + '::' + obj[p] + '\n';
}
}
return str;
}
实际上,以上只是展示了一般方法;您可能希望使用诸如http://phpjs.org/functions/var_export:578或http://phpjs.org/functions/var_dump:604之类的东西
或者,如果你不使用方法(函数作为对象的属性),你可以使用新的标准(但在旧的浏览器中没有实现,尽管你也可以找到一个实用工具来帮助它们),JSON.stringify()。但同样,如果对象使用的函数或其他属性不能序列化为JSON,这将不起作用。
更新:
一个更现代的解决方案是:
function objToString (obj) {
let str = '';
for (const [p, val] of Object.entries(obj)) {
str += `${p}::${val}\n`;
}
return str;
}
or:
function objToString (obj) {
return Object.entries(obj).reduce((str, [p, val]) => {
return `${str}${p}::${val}\n`;
}, '');
}
在检查最后一项时,使用reduce来更改(key,value)元组之间的分隔符sep的修改方法:
/**
* Object to string
* @param {*} obj
* @param {*} k_sep keys separator
* @param {*} v_sep values separator
* @returns
*/
var objectToString: function (obj, k_sep = '=', v_sep = ',') {
const entries = Object.entries(obj);
return entries.reduce((str, [p, val], counter) => {
if (counter < entries.length - 1) {
return `${str}${p}${k_sep}${val}${v_sep}`;
} else {
return `${str}${p}${k_sep}${val}`;
}
}, '');
}
/** * Object to string * @param {*} obj * @param {*} k_sep keys separator * @param {*} v_sep values separator * @returns */ var objectToString = function(obj, k_sep = '=', v_sep = ',') { const entries = Object.entries(obj); return entries.reduce((str, [p, val], counter) => { if (counter < entries.length - 1) { return `${str}${p}${k_sep}${val}${v_sep}`; } else { return `${str}${p}${k_sep}${val}`; } }, ''); } console.log( objectToString({ status_code: 200, execute_time: 0.1, ip: '1270.0.0.1' }, ':', ",")) console.log( objectToString({ status_code: 200, execute_time: 0.1, ip: '1270.0.0.1' }, '=', ","))
JSON方法远不如Gecko引擎的. tosource()原语。
有关比较测试,请参阅SO文章响应。
同样,上面的答案指的是http://forums.devshed.com/javascript-development-115/tosource-with-arrays-in-ie-386109.html,它像JSON一样(另一篇文章http://www.davidpirek.com/blog/object-to-string-how-to-deserialize-json通过“ExtJs JSON编码源代码”使用)不能处理循环引用,并且是不完整的。下面的代码显示了它的(欺骗的)限制(修正为处理无内容的数组和对象)。
(直接链接到//forums.devshed.com/中的代码…/ tosource - -数组在ie - 386109)
javascript:
Object.prototype.spoof=function(){
if (this instanceof String){
return '(new String("'+this.replace(/"/g, '\\"')+'"))';
}
var str=(this instanceof Array)
? '['
: (this instanceof Object)
? '{'
: '(';
for (var i in this){
if (this[i] != Object.prototype.spoof) {
if (this instanceof Array == false) {
str+=(i.match(/\W/))
? '"'+i.replace('"', '\\"')+'":'
: i+':';
}
if (typeof this[i] == 'string'){
str+='"'+this[i].replace('"', '\\"');
}
else if (this[i] instanceof Date){
str+='new Date("'+this[i].toGMTString()+'")';
}
else if (this[i] instanceof Array || this[i] instanceof Object){
str+=this[i].spoof();
}
else {
str+=this[i];
}
str+=', ';
}
};
str=/* fix */(str.length>2?str.substring(0, str.length-2):str)/* -ed */+(
(this instanceof Array)
? ']'
: (this instanceof Object)
? '}'
: ')'
);
return str;
};
for(i in objRA=[
[ 'Simple Raw Object source code:',
'[new Array, new Object, new Boolean, new Number, ' +
'new String, new RegExp, new Function, new Date]' ] ,
[ 'Literal Instances source code:',
'[ [], {}, true, 1, "", /./, function(){}, new Date() ]' ] ,
[ 'some predefined entities:',
'[JSON, Math, null, Infinity, NaN, ' +
'void(0), Function, Array, Object, undefined]' ]
])
alert([
'\n\n\ntesting:',objRA[i][0],objRA[i][1],
'\n.toSource()',(obj=eval(objRA[i][1])).toSource(),
'\ntoSource() spoof:',obj.spoof()
].join('\n'));
显示:
testing:
Simple Raw Object source code:
[new Array, new Object, new Boolean, new Number, new String,
new RegExp, new Function, new Date]
.toSource()
[[], {}, (new Boolean(false)), (new Number(0)), (new String("")),
/(?:)/, (function anonymous() {}), (new Date(1303248037722))]
toSource() spoof:
[[], {}, {}, {}, (new String("")),
{}, {}, new Date("Tue, 19 Apr 2011 21:20:37 GMT")]
and
testing:
Literal Instances source code:
[ [], {}, true, 1, "", /./, function(){}, new Date() ]
.toSource()
[[], {}, true, 1, "", /./, (function () {}), (new Date(1303248055778))]
toSource() spoof:
[[], {}, true, 1, ", {}, {}, new Date("Tue, 19 Apr 2011 21:20:55 GMT")]
and
testing:
some predefined entities:
[JSON, Math, null, Infinity, NaN, void(0), Function, Array, Object, undefined]
.toSource()
[JSON, Math, null, Infinity, NaN, (void 0),
function Function() {[native code]}, function Array() {[native code]},
function Object() {[native code]}, (void 0)]
toSource() spoof:
[{}, {}, null, Infinity, NaN, undefined, {}, {}, {}, undefined]