严格相等运算符将告诉您两个对象类型是否相等。然而,是否有一种方法来判断两个对象是否相等,就像Java中的哈希码值一样?

堆栈溢出问题JavaScript中有hashCode函数吗?类似于这个问题,但需要一个更学术的答案。上面的场景说明了为什么有必要有一个,我想知道是否有等效的解决方案。


当前回答

Const obj = { 名称:“卡尔”, 年龄:15 } Const obj2 = { 名称:“卡尔”, 年龄:15日 } const compareObj = (objects) => { Const res = objects.map((item) => { 返回Object.entries(项).flat . join () () }) 返回res.every((a) => { 返回a === res[0] }) } console.log (compareObj (obj, methoda ()))

其他回答

添加这个版本,因为它处理日期,并有一个流程图显示它是如何工作的。

简而言之,这将检查两个变量是否相等,无论其类型如何。

function isSame (obj1, obj2) {
  const obj1Keys = Object.keys(obj1)
  const obj2Keys = Object.keys(obj2)

  return obj1Keys.length === obj2Keys.length && obj1Keys.every((key) => obj1[key] === obj2[key])
}

这里有很多好的想法!这是我对深度相等的理解。我把它发布在github上,并围绕它写了一些测试。很难涵盖所有可能的情况,有时也没有必要这样做。

我介绍了NaN !== NaN以及循环依赖关系。

https://github.com/ryancat/simple-deep-equal/blob/master/index.js

当然,当我们在它的时候,我会抛出我自己对车轮的重新发明(我为辐条和使用的材料的数量感到自豪):

////////////////////////////////////////////////////////////////////////////////

var equals = function ( objectA, objectB ) {
    var result = false,
        keysA,
        keysB;

    // Check if they are pointing at the same variable. If they are, no need to test further.
    if ( objectA === objectB ) {
        return true;
    }

    // Check if they are the same type. If they are not, no need to test further.
    if ( typeof objectA !== typeof objectB ) {
        return false;
    }

    // Check what kind of variables they are to see what sort of comparison we should make.
    if ( typeof objectA === "object" ) {
        // Check if they have the same constructor, so that we are comparing apples with apples.
        if ( objectA.constructor === objectA.constructor ) {
            // If we are working with Arrays...
            if ( objectA instanceof Array ) {
                // Check the arrays are the same length. If not, they cannot be the same.
                if ( objectA.length === objectB.length ) {
                    // Compare each element. They must be identical. If not, the comparison stops immediately and returns false.
                    return objectA.every(
                        function ( element, i ) {
                            return equals( element, objectB[ i ] );
                        }
                    );
                }
                // They are not the same length, and so are not identical.
                else {
                    return false;
                }
            }
            // If we are working with RegExps...
            else if ( objectA instanceof RegExp ) {
                // Return the results of a string comparison of the expression.
                return ( objectA.toString() === objectB.toString() );
            }
            // Else we are working with other types of objects...
            else {
                // Get the keys as arrays from both objects. This uses Object.keys, so no old browsers here.
                keysA = Object.keys( objectA );

                keysB = Object.keys( objectB );

                // Check the key arrays are the same length. If not, they cannot be the same.
                if ( keysA.length === keysB.length ) {
                    // Compare each property. They must be identical. If not, the comparison stops immediately and returns false.
                    return keysA.every(
                        function ( element ) {
                            return equals( objectA[ element ], objectB[ element ] );
                        }
                    );
                }
                // They do not have the same number of keys, and so are not identical.
                else {
                    return false;
                }
            }
        }
        // They don't have the same constructor.
        else {
            return false;
        }
    }
    // If they are both functions, let us do a string comparison.
    else if ( typeof objectA === "function" ) {
        return ( objectA.toString() === objectB.toString() );
    }
    // If a simple variable type, compare directly without coercion.
    else {
        return ( objectA === objectB );
    }

    // Return a default if nothing has already been returned.
    return result;
};

////////////////////////////////////////////////////////////////////////////////

它会尽可能快地返回false,但当然,对于一个差异嵌套很深的大对象,它可能不那么有效。在我自己的场景中,良好地处理嵌套数组非常重要。

希望它能帮助需要这种“轮子”的人。

const isEqual = function (var1, var2) {
    if (typeof var1 === 'object' && typeof var2 === 'object') {
        // Checking equality for each of the inner values of the objects
        const keys = [...new Set([...Object.keys(var1),...Object.keys(var2)])];
        return keys.every(key => isEqual(var1[key], var2[key]) && isEqual(var2[key], var1[key]));
    } else { // Primitive types (number, boolean etc..)
        return var1 === var2; // Normal equality
    }
}

我在这里看到了很多很好的答案,但我找不到一个简短的函数,所以我创建了一个。 这将检查两个变量是否相等,无论其类型如何。 希望你看得合适。