Question

我有一个函数，通过名称在嵌套对象中查找属性并返回其值。我从这个网站上的另一个问题得到的功能，到目前为止它一直很好用。我看起来像这样：

var _getPropertyValue = function (obj, field) {

    // Create a result
    var result = null;

    // If our object is an array
    if (obj instanceof Array) {

        // For each array item
        for (var i = 0; i < obj.length; i++) {

            // Invoke our function for the current object
            result = _getPropertyValue(obj[i], field);

            // If we have a result
            if (result) {

                // Exit the loop
                break;
            }
        }

    // If we are an object
    } else {

        // For each property in our object
        for (var prop in obj) {

            // If our property matches our value
            if (prop == field) {

                // Return our value
                return obj[prop];
            }

            // If our property is an object or an array
            if (obj[prop] instanceof Object || obj[prop] instanceof Array) {

                // Invoke our function for the current object
                result = _getPropertyValue(obj[prop], field);

                // If we have a result
                if (result) {

                    // Exit the loop
                    break;
                }
            }
        }
    }

    // Return our result
    return result;
};

现在，我想也许如果我有这样的对象：

{
    name: 'test',
    mode: 'default',
    settings: {
        mode: 'auto'
    }
}

使用我的功能，我相信它会找到第一个模式，然后退出该功能。我更喜欢做的是指定字段参数，如下所示：

settings.mode

并直接转到我对象中的那个地方并返回值。有谁知道是否可以这样做？

尽管这个被关闭了。我自己这样回答：

// Private function to get the value of the property
var _getPropertyValue = function (object, notation) {

    // Get all the properties
    var properties = notation.split('.');

    // If we only have one property
    if (properties.length === 1) {

        // Return our value
        return object[properties];
    }

    // Loop through our properties
    for (var property in object) {

        // Make sure we are a property
        if (object.hasOwnProperty(property)) {

            // If we our property name is the same as our first property
            if (property === properties[0]) {

                // Remove the first item from our properties
                properties.splice(0, 1);

                // Create our new dot notation
                var dotNotation = properties.join('.');

                // Find the value of the new dot notation
                return _getPropertyValue(object[property], dotNotation);
            }
        }
    }
};

我进一步改善了这个：

// Private function to get the value of the property
var _getPropertyValue = function (obj, notation) {

    // Get our properties
    var properties = notation.split('.');

    // Use reduce to get the value of the property
    return properties.reduce(function (a, b) {

        // Return our value
        return a[b];
    }, obj);
};

Answer 1

var obj = {
    name: 'test',
    mode: 'default',
    settings: {
        mode: 'auto'
    }
};

var mode = obj.settings.mode;

JavaScript查找属性是重复属性名称

1 个答案: