如何确定部分对象(partial <T>)等于typescript中的原始对象(T)。

function compareTwoObjects<T>(original: T, partial: Partial<T>): boolean {
  return !Object.keys(partial).some((key) => partial[key] !== original[key]);
}

附注:最初我打算提出一个有答案的新问题。但这样的问题已经存在，并被标记为重复题。

虽然这个问题已经得到了充分的回答，但我还缺少一种方法:toJSON接口。

通常你想通过字符串化来比较object，因为这是最快的方法。但往往比较被认为是假的，因为性质的顺序。

const obj1 = {
  a: 1,
  b: 2,
  c: { 
    ca: 1,
    cb: 2
  }
}

const obj2 = {
  b: 2, // changed order with a
  a: 1,
  c: { 
    ca: 1,
    cb: 2
  }
}

JSON.stringify(obj1) === JSON.stringify(obj2) // false

显然，对象被认为是不同的，因为属性a和b的顺序不同。

要解决这个问题，可以实现toJSON接口，并定义一个确定性输出。

const obj1 = {
  a: 1,
  b: 2,
  c: { 
    ca: 1,
    cb: 2
  },
  toJSON() {
    return {
      a: this.a,
      b: this.b,
      c: { 
        ca: this.c.ca,
        cb: this.c.ca
      }
    }
  }
}

const obj2 = {
  b: 2,
  a: 1,
  c: { 
    ca: 1,
    cb: 2
  },
  toJSON() {
    return {
      a: this.a,
      b: this.b,
      c: { 
        ca: this.c.ca,
        cb: this.c.ca
      }
    }
  }
}

JSON.stringify(obj1) === JSON.stringify(obj2) // true

瞧:obj1和obj2的字符串表示被认为是相同的。

TIP

如果你没有直接生成对象的权限，你可以简单地附加toJSON函数:

obj1.toJSON = function() {
  return {
    a: this.a,
    b: this.b,
    c: { 
      ca: this.c.ca,
      cb: this.c.ca
    }
  }
}

obj2.toJSON = function() {
  return {
    a: this.a,
    b: this.b,
    c: { 
      ca: this.c.ca,
      cb: this.c.ca
    }
  }
}

JSON.stringify(obj1) === JSON.stringify(obj2) // true

需要一个比已经发布的更通用的对象比较函数，我炮制了以下。批判赞赏……

Object.prototype.equals = function(iObj) {
  if (this.constructor !== iObj.constructor)
    return false;
  var aMemberCount = 0;
  for (var a in this) {
    if (!this.hasOwnProperty(a))
      continue;
    if (typeof this[a] === 'object' && typeof iObj[a] === 'object' ? !this[a].equals(iObj[a]) : this[a] !== iObj[a])
      return false;
    ++aMemberCount;
  }
  for (var a in iObj)
    if (iObj.hasOwnProperty(a))
      --aMemberCount;
  return aMemberCount ? false : true;
}

从我的个人库中取出，我经常用它来工作。下面的函数是一个宽大的递归深度等号，它不检查

阶级平等 继承的值 价值观严格平等

我主要用这个来检查我是否得到了对各种API实现的相等的回复。可能会出现实现差异(如字符串与数字)和额外的空值。

它的实现非常简单(如果去掉所有注释的话)

/** Recursively check if both objects are equal in value *** *** This function is designed to use multiple methods from most probable *** (and in most cases) valid, to the more regid and complex method. *** *** One of the main principles behind the various check is that while *** some of the simpler checks such as == or JSON may cause false negatives, *** they do not cause false positives. As such they can be safely run first. *** *** # !Important Note: *** as this function is designed for simplified deep equal checks it is not designed *** for the following *** *** - Class equality, (ClassA().a = 1) maybe valid to (ClassB().b = 1) *** - Inherited values, this actually ignores them *** - Values being strictly equal, "1" is equal to 1 (see the basic equality check on this) *** - Performance across all cases. This is designed for high performance on the *** most probable cases of == / JSON equality. Consider bench testing, if you have *** more 'complex' requirments *** *** @param objA : First object to compare *** @param objB : 2nd object to compare *** @param .... : Any other objects to compare *** *** @returns true if all equals, or false if invalid *** *** @license Copyright by eugene@picoded.com, 2012. *** Licensed under the MIT license: http://opensource.org/licenses/MIT **/ function simpleRecusiveDeepEqual(objA, objB) { // Multiple comparision check //-------------------------------------------- var args = Array.prototype.slice.call(arguments); if(args.length > 2) { for(var a=1; a<args.length; ++a) { if(!simpleRecusiveDeepEqual(args[a-1], args[a])) { return false; } } return true; } else if(args.length < 2) { throw "simpleRecusiveDeepEqual, requires atleast 2 arguments"; } // basic equality check, //-------------------------------------------- // if this succed the 2 basic values is equal, // such as numbers and string. // // or its actually the same object pointer. Bam // // Note that if string and number strictly equal is required // change the equality from ==, to === // if(objA == objB) { return true; } // If a value is a bsic type, and failed above. This fails var basicTypes = ["boolean", "number", "string"]; if( basicTypes.indexOf(typeof objA) >= 0 || basicTypes.indexOf(typeof objB) >= 0 ) { return false; } // JSON equality check, //-------------------------------------------- // this can fail, if the JSON stringify the objects in the wrong order // for example the following may fail, due to different string order: // // JSON.stringify( {a:1, b:2} ) == JSON.stringify( {b:2, a:1} ) // if(JSON.stringify(objA) == JSON.stringify(objB)) { return true; } // Array equality check //-------------------------------------------- // This is performed prior to iteration check, // Without this check the following would have been considered valid // // simpleRecusiveDeepEqual( { 0:1963 }, [1963] ); // // Note that u may remove this segment if this is what is intended // if( Array.isArray(objA) ) { //objA is array, objB is not an array if( !Array.isArray(objB) ) { return false; } } else if( Array.isArray(objB) ) { //objA is not array, objB is an array return false; } // Nested values iteration //-------------------------------------------- // Scan and iterate all the nested values, and check for non equal values recusively // // Note that this does not check against null equality, remove the various "!= null" // if this is required var i; //reuse var to iterate // Check objA values against objB for (i in objA) { //Protect against inherited properties if(objA.hasOwnProperty(i)) { if(objB.hasOwnProperty(i)) { // Check if deep equal is valid if(!simpleRecusiveDeepEqual( objA[i], objB[i] )) { return false; } } else if(objA[i] != null) { //ignore null values in objA, that objB does not have //else fails return false; } } } // Check if objB has additional values, that objA do not, fail if so for (i in objB) { if(objB.hasOwnProperty(i)) { if(objB[i] != null && !objA.hasOwnProperty(i)) { //ignore null values in objB, that objA does not have //else fails return false; } } } // End of all checks //-------------------------------------------- // By reaching here, all iteration scans have been done. // and should have returned false if it failed return true; } // Sanity checking of simpleRecusiveDeepEqual (function() { if( // Basic checks !simpleRecusiveDeepEqual({}, {}) || !simpleRecusiveDeepEqual([], []) || !simpleRecusiveDeepEqual(['a'], ['a']) || // Not strict checks !simpleRecusiveDeepEqual("1", 1) || // Multiple objects check !simpleRecusiveDeepEqual( { a:[1,2] }, { a:[1,2] }, { a:[1,2] } ) || // Ensure distinction between array and object (the following should fail) simpleRecusiveDeepEqual( [1963], { 0:1963 } ) || // Null strict checks simpleRecusiveDeepEqual( 0, null ) || simpleRecusiveDeepEqual( "", null ) || // Last "false" exists to make the various check above easy to comment in/out false ) { alert("FATAL ERROR: simpleRecusiveDeepEqual failed basic checks"); } else { //added this last line, for SO snippet alert on success alert("simpleRecusiveDeepEqual: Passed all checks, Yays!"); } })();

是的，另一个答案……

Object.prototype.equals = function (object) { if (this.constructor !== object.constructor) return false; if (Object.keys(this).length !== Object.keys(object).length) return false; var obk; for (obk in object) { if (this[obk] !== object[obk]) return false; } return true; } var aaa = JSON.parse('{"name":"mike","tel":"1324356584"}'); var bbb = JSON.parse('{"tel":"1324356584","name":"mike"}'); var ccc = JSON.parse('{"name":"mike","tel":"584"}'); var ddd = JSON.parse('{"name":"mike","tel":"1324356584", "work":"nope"}'); $("#ab").text(aaa.equals(bbb)); $("#ba").text(bbb.equals(aaa)); $("#bc").text(bbb.equals(ccc)); $("#ad").text(aaa.equals(ddd)); <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> aaa equals bbb? <span id="ab"></span> <br/> bbb equals aaa? <span id="ba"></span> <br/> bbb equals ccc? <span id="bc"></span> <br/> aaa equals ddd? <span id="ad"></span>

我使用这个可比函数来生成JSON可比的对象副本:

Var可比= o => (typeof o != '对象' || !o)?o: 种(o) .sort()。减少((c键)= > (c[主要]=可比(o(例子)),c), {}); / /演示: var = {1, c: 4 b:[2、3],d: {e:“5”,f:零}}; var b = {b:[2、3],c: 4 d: {f: null, e:“5”},答:1}; console.log (JSON.stringify(可比(a))); console.log (JSON.stringify(可比(b))); console.log(JSON.stringify(comparable(a)) == JSON.stringify(comparable(b))); < div id = " div " > < / div >

在测试中很方便(大多数测试框架都有一个is函数)。如。

is(JSON.stringify(comparable(x)), JSON.stringify(comparable(y)), 'x must match y');

如果捕捉到差异，则记录字符串，使差异可见:

x must match y
got      {"a":1,"b":{"0":2,"1":3},"c":7,"d":{"e":"5","f":null}},
expected {"a":1,"b":{"0":2,"1":3},"c":4,"d":{"e":"5","f":null}}.