从javascript对象中删除冗余属性 [英] Remove redundant properties from javascript object

问题描述

可能重复：

如何从多深度JavaScript对象中删除空属性？

我想从对象中删除所有空属性（包括空字符串数组）。

I'd like to remove all empty properties (including arrays of empty strings) from an object.

{ "someString" : "some text", "someObject" : { "array" : [ "", "" ] } }

例如我想从这个示例对象中删除整个分支someObject。

E.g. I'd like to remove the entire branch "someObject" from this example object.

我应该如何使用javascript进行此操作？

How should I go about doing this with javascript?

我可以编写一个递归迭代每个属性并删除空属性的函数，但在上面的示例对象中，不会删除包含空字符串的数组。

I can write a function that iterates of over each property recursively and removes empty ones, but in the example object above the array containing empty strings would not be removed.

我应该清楚，我正在寻找一个递归函数来处理比例子更复杂的对象。任意组合中的多个级别的字符串，对象和数组。

I should be clear, I am looking to write a recursive function that will handle far more complex objects than the example. Multiple levels of strings, objects and arrays in any combination.

问题是递归函数从顶部开始并向下穿过对象。因此，在一个非常长（并且是多余的）分支的末尾的空字符串将被删除，但分支本身不会。

The problem is that a recursive function starts at the top and works its way down through the object. So an empty string at the end of a very long (and otherwise redundant) branch, will be deleted but the branch itself wont.

推荐答案

到达底部后，只需如下所示遍历到根：

After reaching bottom, just traverse back to the root like so:

(function () {
    Object.removeEmptiness = removeEmptiness;

    function isArray(obj) {
        return obj && Object.prototype.toString.call(obj) === "[object Array]" || false;
    }

    function isObject(obj) {
        return obj && typeof obj == "object" || false;
    }

    function removeEmptiness(root, undef) {
        var removeProps;
        removeProps = function (obj, key, parent) {
            var i, isFullyEmpty = true,
                value;
            if (isArray(obj)) {
                //.length not cached on purpose
                for (i = 0; i < obj.length; ++i) {
                    value = obj[i];
                    if (isObject(value)) {
                        removeProps(value, i, obj);
                        isFullyEmpty = false;
                    } else if (value === "" || value === undef) {
                        obj.splice(i--, 1);
                    } else {
                        isFullyEmpty = false;
                    }
                }
            } else {
                for (i in obj) {
                    value = obj[i];
                    if (isObject(value)) {
                        removeProps(value, i, obj);
                        isFullyEmpty = false;
                    } else if (value === "" || value === undef) {
                        delete obj[i];
                    } else {
                        isFullyEmpty = false;
                    }
                }
            }
            if (key !== undef && isFullyEmpty) {
                delete parent[key];
                removeProps(root);
            }
        };
        removeProps(root);
        return root;
    }
})();

测试套房：

var obj = { "someString" : "some text", "someObject2" : {"k":"", "v": ["k"] }, "someArray3": [{}, ["","",""] ], "someObject" : { "array" : [ "", "", {"hello": ["",""] } ] } };
Object.removeEmptiness( obj );
console.log( JSON.stringify( obj ) );

//"{"someString":"some text","someObject2":{"v":["k"]}}"

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