A simple JSON stringify function which requires Array.prototype.map method.
The following users provided lots of ideas and improvements of the code.
@Kambfhase, @hartrock, @atk, @haochi, @jed
Actually, I just provided a deficient version at first. The other versions were created by these users(especially @atk). You may see the discussion below.
| function f( | |
| a, // input (expect object) | |
| b, // placeholder | |
| c // placeholder | |
| ){ | |
| for (b in | |
| // if the input is an object, assign an empty array to c and loop through the properties of it; | |
| // otherwise assign false to c and iterate over nothing. | |
| // but since it's just a roughly checking, a string "[object Object]" will falsely be identified as object, | |
| // and starts the iteration in most of the browsers - | |
| // as properties on strings can be accessed like arrays(except lower IE version, e.g. IE7). | |
| // (reference: http://kangax.github.com/es5-compat-table/#property-access-on-strings). | |
| // anyway, the function still works although there may be unwanted loopings with a bit slower. | |
| (c = a == '' + {} && []) && a | |
| ) | |
| // fill array with object-style key: value pairs, call ourself recursively to escape keys and values. | |
| c.push(f(b) + ':' + f(a[b])); | |
| // check if the input is a string, | |
| return '' + a === a ? | |
| // output as a string literal; | |
| '"' + a + '"' : | |
| // otherwise check if the input is present and an array (has .map), | |
| a && a.map ? | |
| // output as an array literal; | |
| '[' + a.map(f) + ']' : | |
| // otherwise check if the input is an object (c is an array rather than false), | |
| c ? | |
| // output as an object literal; | |
| '{' + c + '}' : | |
| // otherwise use plain coercion (mostly for number/boolean/null literals). | |
| a | |
| } |
| function f(a,b,c){for(b in(c=a==""+{}&&[])&&a)c.push(f(b)+":"+f(a[b]));return""+a===a?'"'+a+'"':a&&a.map?"["+a.map(f)+"]":c?"{"+c+"}":a} |
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| Version 2, December 2004 | |
| Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE> | |
| Everyone is permitted to copy and distribute verbatim or modified | |
| copies of this license document, and changing it is allowed as long | |
| as the name is changed. | |
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION | |
| 0. You just DO WHAT THE FUCK YOU WANT TO. |
| { | |
| "name": "JSON stringify", | |
| "description": "A JSON stringify function", | |
| "keywords": [ | |
| "JSON", | |
| "stringify" | |
| ] | |
| } |
| <!DOCTYPE html> | |
| <title>JSON stringify</title> | |
| <div>Expected value: <b>{"a":123,"b":true,"c":false,"d":null,"e":{"a":"some text"},"f":[1,2,3],"g":["eins","zwei","drei"],"h":[{"one":1},{"one":1,"two":2}],"i":[{"one":1},{"one":1,"two":[{"three":3},[1,2,3]]}]}</b></div> | |
| <div>Actual value: <b id="ret"></b></div> | |
| <script> | |
| var myFunction = function f(a,b,c){for(b in(c=a==""+{}&&[])&&a)c.push(f(b)+":"+f(a[b]));return""+a===a?'"'+a+'"':a&&a.map?"["+a.map(f)+"]":c?"{"+c+"}":a}; | |
| document.getElementById( "ret" ).innerHTML = myFunction({ | |
| a: 123, | |
| b: true, | |
| c: false, | |
| d: null, | |
| e: {a: "some text"}, | |
| f: [1, 2, 3], | |
| g: ["eins", "zwei", "drei"], | |
| h: [{one:1}, {"one":1, two:2}], | |
| i: [{one:1}, { "one":1, two:[ {three:3}, [1,2,3] ] } ] | |
| }) | |
| </script> |
I have to admit that it's hard to do so in 140 bytes :-(
Maybe the escaped special characters can be escaped themselves first, like:
\n to \\n.
i'm kinda late to this one, but can't you save two bytes by turning
/t]/.test(a)into
(a=={}+"")?
nice idea! Yes, that would probably work:
function f(a,b,c){for(b in(a==''+{}&&[])&&a)c.push(f(b)+':'+f(a[b]));return''+a===a?'"'+a+'"':a&&a.map?'['+a.map(f)+']':c?'{'+c+'}':a}
@atk are you sure about that operator precedence?
@jed + > == > &&, so this should work, yes. I have to admit I printed out the sheet of the precedence order from mozilla documentation.
So.... nobody seems to have mentioned the failure case with strings containing ".
It was obvious to us that the contents of strings are not correctly escaped, so we didn't mention it. We're still in the process of golfing for more space for the necessary filter.
'' + a === a could be shortened to a && a.sub (or am I missing something?)
that will disable support for non-browser environments like (Node-js) Rhino
Ah, right. Bummer. And .trim won't work in older JS implementations. Too bad...
And so is Array#map...
But Array#map will work in node.js - and for older implementations we already have a working polyfill.
In that way, we have polyfill for trim as well.
You should use a.pop instead of a.map as in DOMinate. Much better browser compatibility!
@adius: doesn't help, because we'll need a.map anyway. A working version (alas, with 214bytes too long) is here:
function s(a,b,c){for(b in(c=a==''+{}&&[])&&a)c.push(s(b)+':'+s(a[b]));return''+a===a?'"'+a.replace(/[\x00-\x32\\]/g,function(x){return'\x'+x.charCodeAt().toString(16)})+'"':a&&a.map?'['+a.map(s)+']':c?'{'+c+'}':a}
I've not yet tested if it still works if you replace function(x){return'\x'+x.charCodeAt().toString(16)} with function(x){return escape(x).replace(/%/g,'\\x')}, saving 2 further bytes.
This function will still fail on escaped special characters like \n or \t :-(
http://twitter.com/garethheyes/status/95511347042856960