对其他漂亮的Ruby打印机不满意，我编写了自己的（NeatJSON），然后将其移植到JavaScript中，其中包括免费的在线格式化程序。该代码在MIT许可下是免费的（非常宽松）。
功能（全部可选）：
- 设置线宽并以使对象和数组在适合时保持在同一行上的方式进行换行，在不对齐时每行换一个值。
- 如果愿意，可以对对象键进行排序。
- 对齐对象键（将冒号对齐）。
- 将浮点数格式化为特定的小数位数，而不会弄乱整数。
- “短”换行模式将左括号和右括号与括号放在与值相同的行上，从而提供了某些格式。
- 对冒号和逗号前后括号内的数组和对象的间距进行粒度控制。
- 该功能可用于Web浏览器和Node.js。
我将在此处复制源代码，以便它不仅是指向库的链接，而且我建议您转到GitHub项目页面，因为该页面将保持最新，而下面的代码将不会更新。
(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);
