使用node.js比较两个对象

Question

Am trying to compare two objects using node.js . ie in the below code am comparing feature and features1

var im = require('imagemagick');

var fs = require("fs");

im.identify('/home/ushu/dev/filesize/colorlaser-246154946-output.pdf', function(err, features) {
  if (err) throw err;
  console.log(features);
  im.identify('/home/ushu/dev/filesize/test.pdf', function(err, features1) {
    if (err) throw err;
    console.log("-------------------------------------------------")
    console.log(features1);
    if (features != features1) {
      console.log("not eqqq")
    }
  });

});

console.log(feature) prints the following values

{ '2': '( 3084, 3084, 3084,65535) #0C0C0C0C0C0C rgba(12,12,12,1)',
  '4': '(62451,62451,62451,65535) #F3F3F3F3F3F3 rgba(243,243,243,1)',
    '389490': '(65535,65535,65535,65535) #FFFFFFFFFFFF white'
  format: 'PDF',
  class: 'DirectClass',
  geometry: '612x792+0+0',
  resolution: '72x72',
  'print size': '8.5x11',
  units: 'Undefined',
  type: 'PaletteMatte',
  endianess: 'Undefined',
  colorspace: 'RGB',
  depth: 16,
  'channel depth': { red: '8-bit', green: '8-bit', blue: '8-bit', alpha: '1-bit' },
  'channel statistics': 
   { red: 
      { min: '0 (0)',
        max: '65535 (1)',
        mean: '60171.8 (0.918163)',
        'standard deviation': '15774.2 (0.240699)',
        kurtosis: '7.43399',
        skewness: '-2.96721' },
     green: 
      { min: '0 (0)',
        max: '65535 (1)',
        mean: '60171.8 (0.918163)',
        'standard deviation': '15774.2 (0.240699)',
        kurtosis: '7.43399',
        skewness: '-2.96721' }
     },
  'image statistics': 
   { overall: 
      { min: '0 (0)',
        max: '65535 (1)',
        mean: '44566.9 (0.680048)',
        'standard deviation': '14064.6 (0.214613)',
        kurtosis: '28.682',
        skewness: '-6.99615' } },
  histogram: 
   { '34': '( 2313, 2313, 2313,65535) #090909090909 rgba(9,9,9,1)',
     '289': '( 1799, 1799, 1799,65535) #070707070707 rgba(7,7,7,1)',
     '5755': '(    0,    0,    0,65535) #000000000000 black' },
  'rendering intent': 'Undefined',
  interlace: 'None',
  'background color': 'white',
  'border color': 'rgba(223,223,223,1)',
  'matte color': 'grey74',
  'transparent color': 'none',
  compose: 'Over',
  'page geometry': '612x792+0+0',
  dispose: 'Undefined',
  iterations: '0',
  compression: 'Undefined',
  orientation: 'Undefined',
  properties: 
   { 'date:create': '2014-10-28T12:18:40+06:00',
     'date:modify': '2014-10-28T12:18:40+06:00',
     'pdf:hiresboundingbox': '612x792+0+0',
     'pdf:version': 'PDF-1.3',
     signature: '3a281605e05aa1bd74105887caeaddda4dfac3c78716ac9d1309f3570e4c2368' },
  profiles: 
   { 'profile-icc': '2576 bytes',
     'artifex software srgb icc profile': {} },
  artifacts: { verbose: 'true' },
  tainted: 'False',
  filesize: '59.2KBB',
  'number pixels': '485KB',
  'pixels per second': '48.47MB',
  'user time': '0.020u',
  'elapsed time': '0:01.010',
  version: 'ImageMagick 6.6.9-7 2012-08-17 Q16 http://www.imagemagick.org',
  width: 612,
  height: 792 }

and

console.log(features1) prints

{ '499911': '(65535,65535,65535,    0) #FFFFFFFFFFFF0000 rgba(255,255,255,0)',
  format: 'PDF',
  class: 'DirectClass',
  geometry: '596x842+0+0',
  resolution: '72x72',
  'print size': '8.27778x11.6944',
  units: 'Undefined',
  type: 'Bilevel',
  'base type': 'Bilevel',
  endianess: 'Undefined',
  colorspace: 'RGB',
  depth: 16,
  'channel depth': { gray: '1-bit', alpha: '4-bit' },
  'channel statistics': 
   { gray: 
      { min: '0 (0)',
        max: '65535 (1)',
        mean: '65284.1 (0.996172)',
        'standard deviation': '4046.92 (0.0617521)',
        kurtosis: '256.239',
        skewness: '-16.0698' },
     alpha: 
      { min: '0 (0)',
        max: '65535 (1)',
        mean: '199.892 (0.00305016)',
        'standard deviation': '3454.01 (0.0527048)',
        kurtosis: '329.769',
        skewness: '-18.0427' } },
  alpha: 'rgba(255,255,255,0)   #FFFFFFFFFFFF0000',
  histogram: 
   { '18': '(    0,    0,    0,43690) #000000000000AAAA rgba(0,0,0,0.666667)',
     '24': '(    0,    0,    0,26214) #0000000000006666 rgba(0,0,0,0.4)'
      },
  'rendering intent': 'Undefined',
  interlace: 'None',
  'background color': 'white',
  'border color': 'rgba(223,223,223,1)',
  'matte color': 'grey74',
  'transparent color': 'none',
  compose: 'Over',
  'page geometry': '596x842+0+0',
  dispose: 'Undefined',
  iterations: '0',
  compression: 'Undefined',
  orientation: 'Undefined',
  properties: 
   { 'date:create': '2014-10-28T12:18:41+06:00',
     'date:modify': '2014-10-28T12:18:41+06:00',
     'pdf:hiresboundingbox': '596x842+0+0',
     'pdf:version': 'PDF-1.4',
     signature: '63e1cbdcc1568c376cb5f8612f4034de008add9fe8492e4d378ea176cb8e2eab' },
  profiles: 
   { 'profile-icc': '2576 bytes',
     'artifex software srgb icc profile': {} },
  artifacts: { verbose: 'true' },
  tainted: 'False',
  filesize: '8.21KBB',
  'number pixels': '502KB',
  'pixels per second': '50.18MB',
  'user time': '0.010u',
  'elapsed time': '0:01.009',
  version: 'ImageMagick 6.6.9-7 2012-08-17 Q16 http://www.imagemagick.org',
  width: 596,
  height: 842 }

these printed values are not equal.

Using node.js how can i compare these outputted values are equal

Answer 1

You can use lodash's isEqual() to compare 2 objects. Here is an example from lodash's document:

var _ = require('lodash');
var object = { 'name': 'fred' };
var copy = { 'name': 'fred' };

object == copy;
// → false

_.isEqual(object, copy);
// → true

Answer 2

Two objects will return equal in an equality check if they reference the same object in memory, even if the two objects are otherwise identical! So you have to compare the two objects per properties.