检查对象javascript中是否存在嵌套属性 [英] Checking existence of nested property in an object javascript

问题描述

我已经回顾了这个问题的一些答案，但是，我想以不同的方式提出我的问题。

I have already reviewed some of the answers to such question, however, I want to ask my question differently.

让我们说我们有一个字符串：level1.level2.level3。...表示名为 Obj 的对象中的嵌套属性。

Lets say we have a string like : "level1.level2.level3. ..." that indicates a nested property in an object called Obj.

关键是我们可能知道此字符串中存在多少嵌套属性。例如，它可能是level1.level2或level1.level2.level3.level4。

The point is that we may not know that how many nested properties exist in this string. For instance, it may be "level1.level2" or "level1.level2.level3.level4".

现在，我想要一个给出 Obj的函数和作为输入的属性字符串，只需告诉我们，如果对象中存在这样的嵌套属性（假设输出为true或false）。

Now, I want a function that given the Obj and the string of properties as input, simply tell us that if such a nested property exist in the object or not (lets say true or false as output).

更新：
感谢@Silvinus，我发现了一个小修改的解决方案：

Update: Thanks to @Silvinus, I found the solution with a minor modification:

        private checkNestedProperty(obj, props) {
        var splitted = props.split('.');
        var temp = obj;
        for (var index in splitted) {
            if (temp[splitted[index]] === 'undefined' || !temp[splitted[index]]) return false;
            temp = temp[splitted[index]];
        }
        return true;
    }

推荐答案

你可以探索你的Obj这个函数：

You can explore your Obj with this function :

var fn = function(obj, props) {
        var splited = props.split('.');
        var temp = obj;
        for(var index in splited) {
            if(typeof temp[splited[index]] === 'undefined') return false;
            temp = temp[splited[index]]
        }
           return true
        }

var result = fn({ }, "toto.tata");
console.log(result); // false

var result = fn({ toto: { tata: 17 } }, "toto.tata");
console.log(result); // true

var result = fn({ toto: { tata: { tutu: 17 } } }, "toto.foo.tata");
console.log(result); // false

此函数允许探索Obj的嵌套属性，该属性取决于参数中传递的props

This function allow to explore nested property of Obj that depends of props passed in parameter

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