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April 3, 2017 15:34
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Gist file for comparing two objects
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function deepCompare () { | |
var i, l, leftChain, rightChain; | |
function compare2Objects (x, y) { | |
var p; | |
// remember that NaN === NaN returns false | |
// and isNaN(undefined) returns true | |
if (isNaN(x) && isNaN(y) && typeof x === 'number' && typeof y === 'number') { | |
return true; | |
} | |
// Compare primitives and functions. | |
// Check if both arguments link to the same object. | |
// Especially useful on the step where we compare prototypes | |
if (x === y) { | |
return true; | |
} | |
// Works in case when functions are created in constructor. | |
// Comparing dates is a common scenario. Another built-ins? | |
// We can even handle functions passed across iframes | |
if ((typeof x === 'function' && typeof y === 'function') || | |
(x instanceof Date && y instanceof Date) || | |
(x instanceof RegExp && y instanceof RegExp) || | |
(x instanceof String && y instanceof String) || | |
(x instanceof Number && y instanceof Number)) { | |
return x.toString() === y.toString(); | |
} | |
// At last checking prototypes as good as we can | |
if (!(x instanceof Object && y instanceof Object)) { | |
return false; | |
} | |
if (x.isPrototypeOf(y) || y.isPrototypeOf(x)) { | |
return false; | |
} | |
if (x.constructor !== y.constructor) { | |
return false; | |
} | |
if (x.prototype !== y.prototype) { | |
return false; | |
} | |
// Check for infinitive linking loops | |
if (leftChain.indexOf(x) > -1 || rightChain.indexOf(y) > -1) { | |
return false; | |
} | |
// Quick checking of one object being a subset of another. | |
// todo: cache the structure of arguments[0] for performance | |
for (p in y) { | |
if (y.hasOwnProperty(p) !== x.hasOwnProperty(p)) { | |
return false; | |
} | |
else if (typeof y[p] !== typeof x[p]) { | |
return false; | |
} | |
} | |
for (p in x) { | |
if (y.hasOwnProperty(p) !== x.hasOwnProperty(p)) { | |
return false; | |
} | |
else if (typeof y[p] !== typeof x[p]) { | |
return false; | |
} | |
switch (typeof (x[p])) { | |
case 'object': | |
case 'function': | |
leftChain.push(x); | |
rightChain.push(y); | |
if (!compare2Objects (x[p], y[p])) { | |
return false; | |
} | |
leftChain.pop(); | |
rightChain.pop(); | |
break; | |
default: | |
if (x[p] !== y[p]) { | |
return false; | |
} | |
break; | |
} | |
} | |
return true; | |
} | |
if (arguments.length < 1) { | |
return true; //Die silently? Don't know how to handle such case, please help... | |
// throw "Need two or more arguments to compare"; | |
} | |
for (i = 1, l = arguments.length; i < l; i++) { | |
leftChain = []; //Todo: this can be cached | |
rightChain = []; | |
if (!compare2Objects(arguments[0], arguments[i])) { | |
return false; | |
} | |
} | |
return true; | |
} |
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function deepCompare(){function t(e,r){var f;if(isNaN(e)&&isNaN(r)&&"number"==typeof e&&"number"==typeof r)return!0;if(e===r)return!0;if("function"==typeof e&&"function"==typeof r||e instanceof Date&&r instanceof Date||e instanceof RegExp&&r instanceof RegExp||e instanceof String&&r instanceof String||e instanceof Number&&r instanceof Number)return e.toString()===r.toString();if(!(e instanceof Object&&r instanceof Object))return!1;if(e.isPrototypeOf(r)||r.isPrototypeOf(e))return!1;if(e.constructor!==r.constructor)return!1;if(e.prototype!==r.prototype)return!1;if(n.indexOf(e)>-1||o.indexOf(r)>-1)return!1;for(f in r){if(r.hasOwnProperty(f)!==e.hasOwnProperty(f))return!1;if(typeof r[f]!=typeof e[f])return!1}for(f in e){if(r.hasOwnProperty(f)!==e.hasOwnProperty(f))return!1;if(typeof r[f]!=typeof e[f])return!1;switch(typeof e[f]){case"object":case"function":if(n.push(e),o.push(r),!t(e[f],r[f]))return!1;n.pop(),o.pop();break;default:if(e[f]!==r[f])return!1}}return!0}var e,r,n,o;if(arguments.length<1)return!0;for(e=1,r=arguments.length;r>e;e++)if(n=[],o=[],!t(arguments[0],arguments[e]))return!1;return!0} |
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http://stackoverflow.com/a/1144249/3339876 |
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