Javascript 按字符串对对象数组进行排序，与按不同行为的数值排序

这个问题有点啰嗦，但请耐心听我说

我有一个通用的值比较函数用于。排序：

内部帮助器函数GetGenderantProperty用于通过点路径安全地访问对象上的值：

export function getDescendantProperty(obj: object, path: string) {
  // safely access nested properties if the property of the object is itself, an object

  if (path.includes('.')) {
    return path.split('.').reduce((accumulator: object, part: string) => accumulator && accumulator[part] || undefined, obj);
  }
  else {
    return obj[path];
  }
}

当我使用要排序的字符串对对象数组进行排序时，compareObjectValues按预期工作。当使用数值时，它会失败，并且不会遍历所有要比较的预期值

例如：

describe('on an object that uses a number for sorting', () => {
  it('should return the comparison of the values in the correct order', () => {
    const objects = [
      { id: 4 },
      { id: 0 },
      { id: 2 },
      { id: 3 },
      { id: 1 },
    ];

    const sortedObjects = objects.sort(utils.compareObjectValues('id'));

    expect(sortedObjects).toEqual([{ id: 0 }, { id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }]);
  });
});

业力输出：

LOG: 'comparison', 1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 0 of 2 SUCCESS (0 secs / 0 secs)
LOG: 'comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 0 of 2 SUCCESS (0 secs / 0 secs)
LOG: 'comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 0 of 2 SUCCESS (0 secs / 0 secs)
Chrome 74.0.3729 (Mac OS X 10.14.5) Utils tests When calling `compareObjectValues` on an object that uses a number for sorting should return the comparison of the numbers in the correct order FAILED
        Error: Expected $[0].id = 4 to equal 0.
        Expected $[1].id = 0 to equal 1.
        Expected $[2].id = 1 to equal 2.
        Expected $[3].id = 2 to equal 3.
        Expected $[4].id = 3 to equal 4.
            at <Jasmine>
            at UserContext.<anonymous> (src/app/lib/utils.spec.ts:133:31)
            at ZoneDelegate../node_modules/zone.js/dist/zone.js.ZoneDelegate.invoke (node_modules/zone.js/dist/zone.js:391:1)
            at ProxyZoneSpec.push../node_modules/zone.js/dist/zone-testing.js.ProxyZoneSpec.onInvoke (node_modules/zone.js/dist/zone-testing.js:308:1)
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
Chrome 74.0.3729 (Mac OS X 10.14.5) Utils tests When calling `compareObjectValues` on an object that uses a number for sorting should return the comparison of the numbers in the correct order FAILED
        Error: Expected $[0].id = 4 to equal 0.
        Expected $[1].id = 0 to equal 1.
        Expected $[2].id = 1 to equal 2.
        Expected $[3].id = 2 to equal 3.
        Expected $[4].id = 3 to equal 4.
            at <Jasmine>
            at UserContext.<anonymous> (src/app/lib/utils.spec.ts:133:31)
            at ZoneDelegate../node_modules/zone.js/dist/zone.js.ZoneDelegate.invoke (node_modules/zone.js/dist/zone.js:391:1)
LOG: 'string comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', 1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', 1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', 1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', -1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
LOG: 'string comparison', 1
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 1 of 2 (1 FAILED) (0 secs / 0.159 secs)
Chrome 74.0.3729 (Mac OS X 10.14.5): Executed 2 of 2 (1 FAILED) (0.19 secs / 0.16 secs)
TOTAL: 1 FAILED, 1 SUCCESS
TOTAL: 1 FAILED, 1 SUCCESS
npm ERR! Test failed.  See above for more details.

从日志中可以看到，当处理带有数值的对象时，它在3次迭代后停止。使用字符串值，它处理9

我已验证GetDegenantProperty是否返回预期值。我还验证了，如果我在测试中将函数传递给.sort，手动应用相同的比较，则compareObjectValues的逻辑会按预期工作

---

我在隔离错误时遇到了一些困难，非常感谢您的帮助。

问题在于对属性的延迟检查：

if (!propertyA || !propertyB) return 0;

这在检查某些类型的值时效果很好，但在检查数字时会产生意想不到的结果！0==真，空字符串！==真的等等

改用严格的检查：

if (typeof propertyA === 'undefined' || typeof propertyB === 'undefined') return 0;

---

如果房地产！propertyB{return 0；}让我给它一个tryI应该捕捉到的值。非常感谢你！

if (typeof propertyA === 'undefined' || typeof propertyB === 'undefined') return 0;