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
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' }, '=', ","))
其他回答
使用javascript String()函数
String(yourobject); //returns [object Object]
或stringify ()
JSON.stringify(yourobject)
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' }, '=', ","))
/*
This function is as JSON.Stringify (but if you has not in your js-engine you can use this)
Params:
obj - your object
inc_ident - can be " " or "\t".
show_types - show types of object or not
ident - need for recoursion but you can not set this parameter.
*/
function getAsText(obj, inc_ident, show_types, ident) {
var res = "";
if (!ident)
ident = "";
if (typeof(obj) == "string") {
res += "\"" + obj + "\" ";
res += (show_types == true) ? "/* typeobj: " + typeof(obj) + "*/" : "";
} else if (typeof(obj) == "number" || typeof(obj) == "boolean") {
res += obj;
res += (show_types == true) ? "/* typeobj: " + typeof(obj) + "*/" : "";
} else if (obj instanceof Array) {
res += "[ ";
res += show_types ? "/* typeobj: " + typeof(obj) + "*/" : "";
res += "\r\n";
var new_ident = ident + inc_ident;
var arr = [];
for(var key in obj) {
arr.push(new_ident + getAsText(obj[key], inc_ident, show_types, new_ident));
}
res += arr.join(",\r\n") + "\r\n";
res += ident + "]";
} else {
var new_ident = ident + inc_ident;
res += "{ ";
res += (show_types == true) ? "/* typeobj: " + typeof(obj) + "*/" : "";
res += "\r\n";
var arr = [];
for(var key in obj) {
arr.push(new_ident + '"' + key + "\" : " + getAsText(obj[key], inc_ident, show_types, new_ident));
}
res += arr.join(",\r\n") + "\r\n";
res += ident + "}\r\n";
}
return res;
};
示例:
var obj = {
str : "hello",
arr : ["1", "2", "3", 4],
b : true,
vobj : {
str : "hello2"
}
}
var ForReading = 1, ForWriting = 2;
var fso = new ActiveXObject("Scripting.FileSystemObject")
f1 = fso.OpenTextFile("your_object1.txt", ForWriting, true)
f1.Write(getAsText(obj, "\t"));
f1.Close();
f2 = fso.OpenTextFile("your_object2.txt", ForWriting, true)
f2.Write(getAsText(obj, "\t", true));
f2.Close();
your_object1.txt:
{
"str" : "hello" ,
"arr" : [
"1" ,
"2" ,
"3" ,
4
],
"b" : true,
"vobj" : {
"str" : "hello2"
}
}
your_object2.txt:
{ /* typeobj: object*/
"str" : "hello" /* typeobj: string*/,
"arr" : [ /* typeobj: object*/
"1" /* typeobj: string*/,
"2" /* typeobj: string*/,
"3" /* typeobj: string*/,
4/* typeobj: number*/
],
"b" : true/* typeobj: boolean*/,
"vobj" : { /* typeobj: object*/
"str" : "hello2" /* typeobj: string*/
}
}
循环引用
通过使用下面的替换器，我们可以产生更少冗余的JSON -如果源对象包含对某个对象的多次引用，或者包含循环引用-那么我们通过特殊的路径字符串(类似于JSONPath)引用它-我们如下所示
let s = JSON.stringify(obj, refReplacer());
function refReplacer() { let m = new Map(), v= new Map(), init = null; return function(field, value) { let p= m.get(this) + (Array.isArray(this) ? `[${field}]` : '.' + field); let isComplex= value===Object(value) if (isComplex) m.set(value, p); let pp = v.get(value)||''; let path = p.replace(/undefined\.\.?/,''); let val = pp ? `#REF:${pp[0]=='[' ? '$':'$.'}${pp}` : value; !init ? (init=value) : (val===init ? val="#REF:$" : 0); if(!pp && isComplex) v.set(value, path); return val; } } // --------------- // TEST // --------------- // gen obj with duplicate references let a = { a1: 1, a2: 2 }; let b = { b1: 3, b2: "4" }; let obj = { o1: { o2: a }, b, a }; // duplicate reference a.a3 = [1,2,b]; // circular reference b.b3 = a; // circular reference let s = JSON.stringify(obj, refReplacer(), 4); console.log(s);
奖励:这里是这种序列化的逆函数
function parseRefJSON(json) { let objToPath = new Map(); let pathToObj = new Map(); let o = JSON.parse(json); let traverse = (parent, field) => { let obj = parent; let path = '#REF:$'; if (field !== undefined) { obj = parent[field]; path = objToPath.get(parent) + (Array.isArray(parent) ? `[${field}]` : `${field?'.'+field:''}`); } objToPath.set(obj, path); pathToObj.set(path, obj); let ref = pathToObj.get(obj); if (ref) parent[field] = ref; for (let f in obj) if (obj === Object(obj)) traverse(obj, f); } traverse(o); return o; } // ------------ // TEST // ------------ let s = `{ "o1": { "o2": { "a1": 1, "a2": 2, "a3": [ 1, 2, { "b1": 3, "b2": "4", "b3": "#REF:$.o1.o2" } ] } }, "b": "#REF:$.o1.o2.a3[2]", "a": "#REF:$.o1.o2" }`; console.log('Open Chrome console to see nested fields:'); let obj = parseRefJSON(s); console.log(obj);
由于firefox没有将某些对象stringify为屏幕对象;如果你想有相同的结果，如:JSON.stringify(obj):
function objToString (obj) {
var tabjson=[];
for (var p in obj) {
if (obj.hasOwnProperty(p)) {
tabjson.push('"'+p +'"'+ ':' + obj[p]);
}
} tabjson.push()
return '{'+tabjson.join(',')+'}';
}
