《javascript算法--对象的比较》
方法一:JSON.stringify()
此方法简单,适用于当两个对象的属性顺序相同的时候。
var user1 = {name : "nerd", org: "dev"}; var user2 = {name : "nerd", org: "dev"}; var eq = user1 == user2; alert(eq); // gives false var eq1 = JSON.stringify(user1) == JSON.stringify(user2); alert(eq1); // gives true
方法二:深度比较两个对象
深度比较两个对象,当对象的属性类型相同且属性的值相同(对象的顺序可以不一样),两个对象就相等。
function deepCompare(x, y) { 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; }
参考资料:
1.http://stackoverflow.com/questions/1068834/object-comparison-in-javascript
2.https://segmentfault.com/a/1190000008187911