pretty-print JSON using JavaScript
JavascriptJsonPretty PrintJavascript Problem Overview
How can I display JSON in an easy-to-read (for human readers) format? I'm looking primarily for indentation and whitespace, with perhaps even colors / font-styles / etc.
Javascript Solutions
Solution 1 - Javascript
Pretty-printing is implemented natively in JSON.stringify(). The third argument enables pretty printing and sets the spacing to use:
var str = JSON.stringify(obj, null, 2); // spacing level = 2
If you need syntax highlighting, you might use some regex magic like so:
function syntaxHighlight(json) {
if (typeof json != 'string') {
json = JSON.stringify(json, undefined, 2);
}
json = json.replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>');
return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, function (match) {
var cls = 'number';
if (/^"/.test(match)) {
if (/:$/.test(match)) {
cls = 'key';
} else {
cls = 'string';
}
} else if (/true|false/.test(match)) {
cls = 'boolean';
} else if (/null/.test(match)) {
cls = 'null';
}
return '<span class="' + cls + '">' + match + '</span>';
});
}
See in action here: jsfiddle
Or a full snippet provided below:
function output(inp) {
document.body.appendChild(document.createElement('pre')).innerHTML = inp;
}
function syntaxHighlight(json) {
json = json.replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>');
return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, function (match) {
var cls = 'number';
if (/^"/.test(match)) {
if (/:$/.test(match)) {
cls = 'key';
} else {
cls = 'string';
}
} else if (/true|false/.test(match)) {
cls = 'boolean';
} else if (/null/.test(match)) {
cls = 'null';
}
return '<span class="' + cls + '">' + match + '</span>';
});
}
var obj = {a:1, 'b':'foo', c:[false,'false',null, 'null', {d:{e:1.3e5,f:'1.3e5'}}]};
var str = JSON.stringify(obj, undefined, 4);
output(str);
output(syntaxHighlight(str));
pre {outline: 1px solid #ccc; padding: 5px; margin: 5px; }
.string { color: green; }
.number { color: darkorange; }
.boolean { color: blue; }
.null { color: magenta; }
.key { color: red; }
Solution 2 - Javascript
User Pumbaa80's answer is great if you have an object you want pretty printed. If you're starting from a valid JSON string that you want to pretty printed, you need to convert it to an object first:
var jsonString = '{"some":"json"}';
var jsonPretty = JSON.stringify(JSON.parse(jsonString),null,2);
This builds a JSON object from the string, and then converts it back to a string using JSON stringify's pretty print.
Solution 3 - Javascript
Solution 4 - Javascript
var jsonObj = {"streetLabel": "Avenue Anatole France", "city": "Paris 07", "postalCode": "75007", "countryCode": "FRA", "countryLabel": "France" };
document.getElementById("result-before").innerHTML = JSON.stringify(jsonObj);
In case of displaying in HTML, you should to add a balise <pre></pre>
document.getElementById("result-after").innerHTML = "<pre>"+JSON.stringify(jsonObj,undefined, 2) +"</pre>"
Example:
var jsonObj = {"streetLabel": "Avenue Anatole France", "city": "Paris 07", "postalCode": "75007", "countryCode": "FRA", "countryLabel": "France" };
document.getElementById("result-before").innerHTML = JSON.stringify(jsonObj);
document.getElementById("result-after").innerHTML = "<pre>"+JSON.stringify(jsonObj,undefined, 2) +"</pre>"
div { float:left; clear:both; margin: 1em 0; }
<div id="result-before"></div>
<div id="result-after"></div>
Solution 5 - Javascript
Based on Pumbaa80's answer I have modified the code to use the console.log colours (working on Chrome for sure) and not HTML. Output can be seen inside console. You can edit the _variables inside the function adding some more styling.
function JSONstringify(json) {
if (typeof json != 'string') {
json = JSON.stringify(json, undefined, '\t');
}
var
arr = [],
_string = 'color:green',
_number = 'color:darkorange',
_boolean = 'color:blue',
_null = 'color:magenta',
_key = 'color:red';
json = json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, function (match) {
var style = _number;
if (/^"/.test(match)) {
if (/:$/.test(match)) {
style = _key;
} else {
style = _string;
}
} else if (/true|false/.test(match)) {
style = _boolean;
} else if (/null/.test(match)) {
style = _null;
}
arr.push(style);
arr.push('');
return '%c' + match + '%c';
});
arr.unshift(json);
console.log.apply(console, arr);
}
Here is a bookmarklet you can use:
javascript:function JSONstringify(json) {if (typeof json != 'string') {json = JSON.stringify(json, undefined, '\t');}var arr = [],_string = 'color:green',_number = 'color:darkorange',_boolean = 'color:blue',_null = 'color:magenta',_key = 'color:red';json = json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, function (match) {var style = _number;if (/^"/.test(match)) {if (/:$/.test(match)) {style = _key;} else {style = _string;}} else if (/true|false/.test(match)) {style = _boolean;} else if (/null/.test(match)) {style = _null;}arr.push(style);arr.push('');return '%c' + match + '%c';});arr.unshift(json);console.log.apply(console, arr);};void(0);
Usage:
var obj = {a:1, 'b':'foo', c:[false,null, {d:{e:1.3e5}}]};
JSONstringify(obj);
Edit: I just tried to escape the % symbol with this line, after the variables declaration:
json = json.replace(/%/g, '%%');
But I find out that Chrome is not supporting % escaping in the console. Strange... Maybe this will work in the future.
Cheers!
Solution 6 - Javascript
I use the JSONView Chrome extension (it is as pretty as it gets :):
Edit: added jsonreport.js
I've also released an online stand-alone JSON pretty print viewer, jsonreport.js, that provides a human readable HTML5 report you can use to view any JSON data.
You can read more about the format in New JavaScript HTML5 Report Format.
Solution 7 - Javascript
You can use console.dir(), which is a shortcut for console.log(util.inspect()).
(The only difference is that it bypasses any custom inspect() function defined on an object.)
It uses syntax-highlighting, smart indentation, removes quotes from keys and just makes the output as pretty as it gets.
const object = JSON.parse(jsonString)
console.dir(object, {depth: null, colors: true})
and for the command line:
cat package.json | node -e "process.stdin.pipe(new stream.Writable({write: chunk => console.dir(JSON.parse(chunk), {depth: null, colors: true})}))"
Solution 8 - Javascript
Here's user123444555621's awesome HTML one adapted for terminals. Handy for debugging Node scripts:
function prettyJ(json) {
if (typeof json !== 'string') {
json = JSON.stringify(json, undefined, 2);
}
return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g,
function (match) {
let cls = "\x1b[36m";
if (/^"/.test(match)) {
if (/:$/.test(match)) {
cls = "\x1b[34m";
} else {
cls = "\x1b[32m";
}
} else if (/true|false/.test(match)) {
cls = "\x1b[35m";
} else if (/null/.test(match)) {
cls = "\x1b[31m";
}
return cls + match + "\x1b[0m";
}
);
}
Usage:
// thing = any json OR string of json
prettyJ(thing);
Solution 9 - Javascript
You can use JSON.stringify(your object, null, 2)
The second parameter can be used as a replacer function which takes key and Val as parameters.This can be used in case you want to modify something within your JSON object.
more reference : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
Solution 10 - Javascript
If you are using ES5, simply call JSON.stringify with:
- 2nd arg: replacer; set to null,
- 3rd arg: space; use tab.
JSON.stringify(anObject, null, '\t');
Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
Solution 11 - Javascript
For debugging purpose I use:
console.debug("%o", data);
Solution 12 - Javascript
Unsatisfied with other pretty printers for Ruby, I wrote my own (NeatJSON) and then ported it to JavaScript including a free online formatter. The code is free under MIT license (quite permissive).
Features (all optional):
- Set a line width and wrap in a way that keeps objects and arrays on the same line when they fit, wrapping one value per line when they don't.
- Sort object keys if you like.
- Align object keys (line up the colons).
- Format floating point numbers to specific number of decimals, without messing up the integers.
- 'Short' wrapping mode puts opening and closing brackets/braces on the same line as values, providing a format that some prefer.
- Granular control over spacing for arrays and objects, between brackets, before/after colons and commas.
- Function is made available to both web browsers and Node.js.
I'll copy the source code here so that this is not just a link to a library, but I encourage you to go to the GitHub project page, as that will be kept up-to-date and the code below will not.
(function(exports){
exports.neatJSON = neatJSON;
function neatJSON(value,opts){
opts = opts || {}
if (!('wrap' in opts)) opts.wrap = 80;
if (opts.wrap==true) opts.wrap = -1;
if (!('indent' in opts)) opts.indent = ' ';
if (!('arrayPadding' in opts)) opts.arrayPadding = ('padding' in opts) ? opts.padding : 0;
if (!('objectPadding' in opts)) opts.objectPadding = ('padding' in opts) ? opts.padding : 0;
if (!('afterComma' in opts)) opts.afterComma = ('aroundComma' in opts) ? opts.aroundComma : 0;
if (!('beforeComma' in opts)) opts.beforeComma = ('aroundComma' in opts) ? opts.aroundComma : 0;
if (!('afterColon' in opts)) opts.afterColon = ('aroundColon' in opts) ? opts.aroundColon : 0;
if (!('beforeColon' in opts)) opts.beforeColon = ('aroundColon' in opts) ? opts.aroundColon : 0;
var apad = repeat(' ',opts.arrayPadding),
opad = repeat(' ',opts.objectPadding),
comma = repeat(' ',opts.beforeComma)+','+repeat(' ',opts.afterComma),
colon = repeat(' ',opts.beforeColon)+':'+repeat(' ',opts.afterColon);
return build(value,'');
function build(o,indent){
if (o===null || o===undefined) return indent+'null';
else{
switch(o.constructor){
case Number:
var isFloat = (o === +o && o !== (o|0));
return indent + ((isFloat && ('decimals' in opts)) ? o.toFixed(opts.decimals) : (o+''));
case Array:
var pieces = o.map(function(v){ return build(v,'') });
var oneLine = indent+'['+apad+pieces.join(comma)+apad+']';
if (opts.wrap===false || oneLine.length<=opts.wrap) return oneLine;
if (opts.short){
var indent2 = indent+' '+apad;
pieces = o.map(function(v){ return build(v,indent2) });
pieces[0] = pieces[0].replace(indent2,indent+'['+apad);
pieces[pieces.length-1] = pieces[pieces.length-1]+apad+']';
return pieces.join(',\n');
}else{
var indent2 = indent+opts.indent;
return indent+'[\n'+o.map(function(v){ return build(v,indent2) }).join(',\n')+'\n'+indent+']';
}
case Object:
var keyvals=[],i=0;
for (var k in o) keyvals[i++] = [JSON.stringify(k), build(o[k],'')];
if (opts.sorted) keyvals = keyvals.sort(function(kv1,kv2){ kv1=kv1[0]; kv2=kv2[0]; return kv1<kv2?-1:kv1>kv2?1:0 });
keyvals = keyvals.map(function(kv){ return kv.join(colon) }).join(comma);
var oneLine = indent+"{"+opad+keyvals+opad+"}";
if (opts.wrap===false || oneLine.length<opts.wrap) return oneLine;
if (opts.short){
var keyvals=[],i=0;
for (var k in o) keyvals[i++] = [indent+' '+opad+JSON.stringify(k),o[k]];
if (opts.sorted) keyvals = keyvals.sort(function(kv1,kv2){ kv1=kv1[0]; kv2=kv2[0]; return kv1<kv2?-1:kv1>kv2?1:0 });
keyvals[0][0] = keyvals[0][0].replace(indent+' ',indent+'{');
if (opts.aligned){
var longest = 0;
for (var i=keyvals.length;i--;) if (keyvals[i][0].length>longest) longest = keyvals[i][0].length;
var padding = repeat(' ',longest);
for (var i=keyvals.length;i--;) keyvals[i][0] = padRight(padding,keyvals[i][0]);
}
for (var i=keyvals.length;i--;){
var k=keyvals[i][0], v=keyvals[i][1];
var indent2 = repeat(' ',(k+colon).length);
var oneLine = k+colon+build(v,'');
keyvals[i] = (opts.wrap===false || oneLine.length<=opts.wrap || !v || typeof v!="object") ? oneLine : (k+colon+build(v,indent2).replace(/^\s+/,''));
}
return keyvals.join(',\n') + opad + '}';
}else{
var keyvals=[],i=0;
for (var k in o) keyvals[i++] = [indent+opts.indent+JSON.stringify(k),o[k]];
if (opts.sorted) keyvals = keyvals.sort(function(kv1,kv2){ kv1=kv1[0]; kv2=kv2[0]; return kv1<kv2?-1:kv1>kv2?1:0 });
if (opts.aligned){
var longest = 0;
for (var i=keyvals.length;i--;) if (keyvals[i][0].length>longest) longest = keyvals[i][0].length;
var padding = repeat(' ',longest);
for (var i=keyvals.length;i--;) keyvals[i][0] = padRight(padding,keyvals[i][0]);
}
var indent2 = indent+opts.indent;
for (var i=keyvals.length;i--;){
var k=keyvals[i][0], v=keyvals[i][1];
var oneLine = k+colon+build(v,'');
keyvals[i] = (opts.wrap===false || oneLine.length<=opts.wrap || !v || typeof v!="object") ? oneLine : (k+colon+build(v,indent2).replace(/^\s+/,''));
}
return indent+'{\n'+keyvals.join(',\n')+'\n'+indent+'}'
}
default:
return indent+JSON.stringify(o);
}
}
}
function repeat(str,times){ // http://stackoverflow.com/a/17800645/405017
var result = '';
while(true){
if (times & 1) result += str;
times >>= 1;
if (times) str += str;
else break;
}
return result;
}
function padRight(pad, str){
return (str + pad).substring(0, pad.length);
}
}
neatJSON.version = "0.5";
})(typeof exports === 'undefined' ? this : exports);
Solution 13 - Javascript
Thanks a lot @all! Based on the previous answers, here is another variant method providing custom replacement rules as parameter:
renderJSON : function(json, rr, code, pre){
if (typeof json !== 'string') {
json = JSON.stringify(json, undefined, '\t');
}
var rules = {
def : 'color:black;',
defKey : function(match){
return '<strong>' + match + '</strong>';
},
types : [
{
name : 'True',
regex : /true/,
type : 'boolean',
style : 'color:lightgreen;'
},
{
name : 'False',
regex : /false/,
type : 'boolean',
style : 'color:lightred;'
},
{
name : 'Unicode',
regex : /"(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?/,
type : 'string',
style : 'color:green;'
},
{
name : 'Null',
regex : /null/,
type : 'nil',
style : 'color:magenta;'
},
{
name : 'Number',
regex : /-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/,
type : 'number',
style : 'color:darkorange;'
},
{
name : 'Whitespace',
regex : /\s+/,
type : 'whitespace',
style : function(match){
return ' ';
}
}
],
keys : [
{
name : 'Testkey',
regex : /("testkey")/,
type : 'key',
style : function(match){
return '<h1>' + match + '</h1>';
}
}
],
punctuation : {
name : 'Punctuation',
regex : /([\,\.\}\{\[\]])/,
type : 'punctuation',
style : function(match){
return '<p>________</p>';
}
}
};
if('undefined' !== typeof jQuery){
rules = $.extend(rules, ('object' === typeof rr) ? rr : {});
}else{
for(var k in rr ){
rules[k] = rr[k];
}
}
var str = json.replace(/([\,\.\}\{\[\]]|"(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, function (match) {
var i = 0, p;
if (rules.punctuation.regex.test(match)) {
if('string' === typeof rules.punctuation.style){
return '<span style="'+ rules.punctuation.style + '">' + match + '</span>';
}else if('function' === typeof rules.punctuation.style){
return rules.punctuation.style(match);
} else{
return match;
}
}
if (/^"/.test(match)) {
if (/:$/.test(match)) {
for(i=0;i<rules.keys.length;i++){
p = rules.keys[i];
if (p.regex.test(match)) {
if('string' === typeof p.style){
return '<span style="'+ p.style + '">' + match + '</span>';
}else if('function' === typeof p.style){
return p.style(match);
} else{
return match;
}
}
}
return ('function'===typeof rules.defKey) ? rules.defKey(match) : '<span style="'+ rules.defKey + '">' + match + '</span>';
} else {
return ('function'===typeof rules.def) ? rules.def(match) : '<span style="'+ rules.def + '">' + match + '</span>';
}
} else {
for(i=0;i<rules.types.length;i++){
p = rules.types[i];
if (p.regex.test(match)) {
if('string' === typeof p.style){
return '<span style="'+ p.style + '">' + match + '</span>';
}else if('function' === typeof p.style){
return p.style(match);
} else{
return match;
}
}
}
}
});
if(true === pre)str = '<pre>' + str + '</pre>';
if(true === code)str = '<code>' + str + '</code>';
return str;
}
Solution 14 - Javascript
It works well:
console.table()
Read more here: https://developer.mozilla.org/pt-BR/docs/Web/API/Console/table
Solution 15 - Javascript
Here is a simple JSON format/color component written in React:
const HighlightedJSON = ({ json }: Object) => {
const highlightedJSON = jsonObj =>
Object.keys(jsonObj).map(key => {
const value = jsonObj[key];
let valueType = typeof value;
const isSimpleValue =
["string", "number", "boolean"].includes(valueType) || !value;
if (isSimpleValue && valueType === "object") {
valueType = "null";
}
return (
<div key={key} className="line">
<span className="key">{key}:</span>
{isSimpleValue ? (
<span className={valueType}>{`${value}`}</span>
) : (
highlightedJSON(value)
)}
</div>
);
});
return <div className="json">{highlightedJSON(json)}</div>;
};
See it working in this CodePen: https://codepen.io/benshope/pen/BxVpjo
Hope that helps!
Solution 16 - Javascript
Couldn't find any solution that had good syntax highlighting for the console, so here's my 2p
Install & Add cli-highlight dependency
npm install cli-highlight --save
Define logjson globally
const highlight = require('cli-highlight').highlight
console.logjson = (obj) => console.log(
highlight( JSON.stringify(obj, null, 4),
{ language: 'json', ignoreIllegals: true } ));
Use
console.logjson({foo: "bar", someArray: ["string1", "string2"]});
Solution 17 - Javascript
Douglas Crockford's JSON in JavaScript library will pretty print JSON via the stringify method.
You may also find the answers to this older question useful: https://stackoverflow.com/questions/352098/how-to-pretty-print-json-script
Solution 18 - Javascript
I ran into an issue today with @Pumbaa80's code. I'm trying to apply JSON syntax highlighting to data that I'm rendering in a Mithril view, so I need to create DOM nodes for everything in the JSON.stringify output.
I split the really long regex into its component parts as well.
render_json = (data) ->
# wraps JSON data in span elements so that syntax highlighting may be
# applied. Should be placed in a `whitespace: pre` context
if typeof(data) isnt 'string'
data = JSON.stringify(data, undefined, 2)
unicode = /"(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?/
keyword = /\b(true|false|null)\b/
whitespace = /\s+/
punctuation = /[,.}{\[\]]/
number = /-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/
syntax = '(' + [unicode, keyword, whitespace,
punctuation, number].map((r) -> r.source).join('|') + ')'
parser = new RegExp(syntax, 'g')
nodes = data.match(parser) ? []
select_class = (node) ->
if punctuation.test(node)
return 'punctuation'
if /^\s+$/.test(node)
return 'whitespace'
if /^\"/.test(node)
if /:$/.test(node)
return 'key'
return 'string'
if /true|false/.test(node)
return 'boolean'
if /null/.test(node)
return 'null'
return 'number'
return nodes.map (node) ->
cls = select_class(node)
return Mithril('span', {class: cls}, node)
Code in context on Github here
Solution 19 - Javascript
I'd like to show my jsonAnalyze method here, it does a pretty print of the JSON structure only, but in some cases can be more usefull that printing the whole JSON.
Say you have a complex JSON like this:
let theJson = {
'username': 'elen',
'email': '[email protected]',
'state': 'married',
'profiles': [
{'name': 'elenLove', 'job': 'actor' },
{'name': 'elenDoe', 'job': 'spy'}
],
'hobbies': ['run', 'movies'],
'status': {
'home': {
'ownsHome': true,
'addresses': [
{'town': 'Mexico', 'address': '123 mexicoStr'},
{'town': 'Atlanta', 'address': '4B atlanta 45-48'},
]
},
'car': {
'ownsCar': true,
'cars': [
{'brand': 'Nissan', 'plate': 'TOKY-114', 'prevOwnersIDs': ['4532354531', '3454655344', '5566753422']},
{'brand': 'Benz', 'plate': 'ELEN-1225', 'prevOwnersIDs': ['4531124531', '97864655344', '887666753422']}
]
}
},
'active': true,
'employed': false,
};
Then the method will return the structure like this:
username
email
state
profiles[]
profiles[].name
profiles[].job
hobbies[]
status{}
status{}.home{}
status{}.home{}.ownsHome
status{}.home{}.addresses[]
status{}.home{}.addresses[].town
status{}.home{}.addresses[].address
status{}.car{}
status{}.car{}.ownsCar
status{}.car{}.cars[]
status{}.car{}.cars[].brand
status{}.car{}.cars[].plate
status{}.car{}.cars[].prevOwnersIDs[]
active
employed
So this is the jsonAnalyze() code:
function jsonAnalyze(obj) {
let arr = [];
analyzeJson(obj, null, arr);
return logBeautifiedDotNotation(arr);
function analyzeJson(obj, parentStr, outArr) {
let opt;
if (!outArr) {
return "no output array given"
}
for (let prop in obj) {
opt = parentStr ? parentStr + '.' + prop : prop;
if (Array.isArray(obj[prop]) && obj[prop] !== null) {
let arr = obj[prop];
if ((Array.isArray(arr[0]) || typeof arr[0] == "object") && arr[0] != null) {
outArr.push(opt + '[]');
analyzeJson(arr[0], opt + '[]', outArr);
} else {
outArr.push(opt + '[]');
}
} else if (typeof obj[prop] == "object" && obj[prop] !== null) {
outArr.push(opt + '{}');
analyzeJson(obj[prop], opt + '{}', outArr);
} else {
if (obj.hasOwnProperty(prop) && typeof obj[prop] != 'function') {
outArr.push(opt);
}
}
}
}
function logBeautifiedDotNotation(arr) {
retStr = '';
arr.map(function (item) {
let dotsAmount = item.split(".").length - 1;
let dotsString = Array(dotsAmount + 1).join(' ');
retStr += dotsString + item + '\n';
console.log(dotsString + item)
});
return retStr;
}
}
jsonAnalyze(theJson);
Solution 20 - Javascript
I think you're looking for something like this :
JSON.stringify(obj, null, '\t');
This "pretty-prints" your JSON string, using a tab for indentation.
If you prefer to use spaces instead of tabs, you could also use a number for the number of spaces you'd like :
JSON.stringify(obj, null, 2);
Solution 21 - Javascript
If you need this to work in a textarea the accepted solution will not work.
<textarea id='textarea'></textarea>
$("#textarea").append(formatJSON(JSON.stringify(jsonobject),true));
function formatJSON(json,textarea) {
var nl;
if(textarea) {
nl = " ";
} else {
nl = "<br>";
}
var tab = "    ";
var ret = "";
var numquotes = 0;
var betweenquotes = false;
var firstquote = false;
for (var i = 0; i < json.length; i++) {
var c = json[i];
if(c == '"') {
numquotes ++;
if((numquotes + 2) % 2 == 1) {
betweenquotes = true;
} else {
betweenquotes = false;
}
if((numquotes + 3) % 4 == 0) {
firstquote = true;
} else {
firstquote = false;
}
}
if(c == '[' && !betweenquotes) {
ret += c;
ret += nl;
continue;
}
if(c == '{' && !betweenquotes) {
ret += tab;
ret += c;
ret += nl;
continue;
}
if(c == '"' && firstquote) {
ret += tab + tab;
ret += c;
continue;
} else if (c == '"' && !firstquote) {
ret += c;
continue;
}
if(c == ',' && !betweenquotes) {
ret += c;
ret += nl;
continue;
}
if(c == '}' && !betweenquotes) {
ret += nl;
ret += tab;
ret += c;
continue;
}
if(c == ']' && !betweenquotes) {
ret += nl;
ret += c;
continue;
}
ret += c;
} // i loop
return ret;
}
Solution 22 - Javascript
If you're looking for a nice library to prettify json on a web page...
Prism.js is pretty good.
I found using JSON.stringify(obj, undefined, 2) to get the indentation, and then using prism to add a theme was a good approach.
If you're loading in JSON via an ajax call, then you can run one of Prism's utility methods to prettify
For example:
Prism.highlightAll()
Solution 23 - Javascript
This is nice:
https://github.com/mafintosh/json-markup from mafintosh
const jsonMarkup = require('json-markup')
const html = jsonMarkup({hello:'world'})
document.querySelector('#myElem').innerHTML = html
HTML
<link ref="stylesheet" href="style.css">
<div id="myElem></div>
Example stylesheet can be found here
https://raw.githubusercontent.com/mafintosh/json-markup/master/style.css
Solution 24 - Javascript
To highlight and beautify it in HTML using Bootstrap:
function prettifyJson(json, prettify) {
if (typeof json !== 'string') {
if (prettify) {
json = JSON.stringify(json, undefined, 4);
} else {
json = JSON.stringify(json);
}
}
return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g,
function(match) {
let cls = "<span>";
if (/^"/.test(match)) {
if (/:$/.test(match)) {
cls = "<span class='text-danger'>";
} else {
cls = "<span>";
}
} else if (/true|false/.test(match)) {
cls = "<span class='text-primary'>";
} else if (/null/.test(match)) {
cls = "<span class='text-info'>";
}
return cls + match + "</span>";
}
);
}
Solution 25 - Javascript
based on @user123444555621, just slightly more modern.
const clsMap = [
[/^".*:$/, "key"],
[/^"/, "string"],
[/true|false/, "boolean"],
[/null/, "key"],
[/.*/, "number"],
]
const syntaxHighlight = obj => JSON.stringify(obj, null, 4)
.replace(/&/g, '&')
.replace(/</g, '<')
.replace(/>/g, '>')
.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, match => `<span class="${clsMap.find(([regex]) => regex.test(match))[1]}">${match}</span>`);
you can also specify the colors inside js (no CSS needed)
const clsMap = [
[/^".*:$/, "red"],
[/^"/, "green"],
[/true|false/, "blue"],
[/null/, "magenta"],
[/.*/, "darkorange"],
]
const syntaxHighlight = obj => JSON.stringify(obj, null, 4)
.replace(/&/g, '&')
.replace(/</g, '<')
.replace(/>/g, '>')
.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, match => `<span style="color:${clsMap.find(([regex]) => regex.test(match))[1]}">${match}</span>`);
and a version with less regex
const clsMap = [
[match => match.startsWith('"') && match.endsWith(':'), "red"],
[match => match.startsWith('"'), "green"],
[match => match === "true" || match === "false" , "blue"],
[match => match === "null", "magenta"],
[() => true, "darkorange"],
];
const syntaxHighlight = obj => JSON.stringify(obj, null, 4)
.replace(/&/g, '&')
.replace(/</g, '<')
.replace(/>/g, '>')
.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, match => `<span style="color:${clsMap.find(([fn]) => fn(match))[1]}">${match}</span>`);
Solution 26 - Javascript
it's for Laravel, Codeigniter
Html:
<pre class="jsonPre"> </pre>
Controller: Return the JSON value from the controller as like as
return json_encode($data, JSON_PRETTY_PRINT);
In script:
<script> $('.jsonPre').html(result); </script>
result will be
Solution 27 - Javascript
Here is how you can print without using native function.
function pretty(ob, lvl = 0) {
let temp = [];
if(typeof ob === "object"){
for(let x in ob) {
if(ob.hasOwnProperty(x)) {
temp.push( getTabs(lvl+1) + x + ":" + pretty(ob[x], lvl+1) );
}
}
return "{\n"+ temp.join(",\n") +"\n" + getTabs(lvl) + "}";
}
else {
return ob;
}
}
function getTabs(n) {
let c = 0, res = "";
while(c++ < n)
res+="\t";
return res;
}
let obj = {a: {b: 2}, x: {y: 3}};
console.log(pretty(obj));
/*
{
a: {
b: 2
},
x: {
y: 3
}
}
*/
Solution 28 - Javascript
The simplest way to display an object for debugging purposes:
console.log("data",data) // lets you unfold the object manually
If you want to display the object in the DOM, you should consider that it could contain strings that would be interpreted as HTML. Therefore, you need to do some escaping...
var s = JSON.stringify(data,null,2) // format
var e = new Option(s).innerHTML // escape
document.body.insertAdjacentHTML('beforeend','<pre>'+e+'</pre>') // display
Solution 29 - Javascript
<!-- here is a complete example pretty print with more space between lines-->
<!-- be sure to pass a json string not a json object -->
<!-- use line-height to increase or decrease spacing between json lines -->
<style type="text/css">
.preJsonTxt{
font-size: 18px;
text-overflow: ellipsis;
overflow: hidden;
line-height: 200%;
}
.boxedIn{
border: 1px solid black;
margin: 20px;
padding: 20px;
}
</style>
<div class="boxedIn">
<h3>Configuration Parameters</h3>
<pre id="jsonCfgParams" class="preJsonTxt">{{ cfgParams }}</pre>
</div>
<script language="JavaScript">
$( document ).ready(function()
{
$(formatJson);
<!-- this will do a pretty print on the json cfg params -->
function formatJson() {
var element = $("#jsonCfgParams");
var obj = JSON.parse(element.text());
element.html(JSON.stringify(obj, undefined, 2));
}
});
</script>
Solution 30 - Javascript
Quick pretty human-readable JSON output in 1 line code (without colors):
document.documentElement.innerHTML='<pre>'+JSON.stringify(obj, null, 2)+'</pre>';