getValue (o, key1, key2, key3, key4, key5) {
    try {
      return o[key1][key2][key3][key4][key5]
    } catch (e) {
      return null
    }
}

这是我从奥利弗·斯蒂尔那里学到的一个模式：

var level3 = (((test || {}).level1 || {}).level2 || {}).level3;
alert( level3 );

事实上，整篇文章讨论了如何在javascript中实现这一点。他决定使用上面的语法（一旦你习惯了，它就不那么难读了）作为成语。

另一个ES5解决方案：

function hasProperties(object, properties) {
    return !properties.some(function(property){
        if (!object.hasOwnProperty(property)) {
            return true;
        }
        object = object[property];
        return false;
    });
}

根据@Stephane LaFlèche的回答，我提出了另一个剧本版本。

JSFiddle演示

var obj = {"a":{"b":{"c":"Hello World"}},"resTest":"potato","success":"This path exists"};
checkForPathInObject = function(object,path,value) {
        var pathParts   = path.split("."),
            result      = false;
        // Check if required parameters are set; if not, return false
        if(!object || typeof object == 'undefined' || !path || typeof path != 'string')
            return false;
        /* Loop through object keys to find a way to the path or check for value
         * If the property does not exist, set result to false
         * If the property is an object, update @object
         * Otherwise, update result */
        for(var i=0;i<pathParts.length;i++){
            var currentPathPart = pathParts[i];
            if(!object.hasOwnProperty( currentPathPart )) {
                result = false;
            } else if (object[ currentPathPart ] && path == pathParts[i]) {
                result = pathParts[i];
                break;
            } else if(typeof object[ currentPathPart ] == 'object') {
                object = object[ currentPathPart ];
            } else {
                result = object[ currentPathPart ];
            }
        }
        /* */
        if(typeof value != 'undefined' && value == result)
            return true;
        return result;
};
// Uncomment the lines below to test the script
// alert( checkForPathInObject(obj,'a.b.c') ); // Results "Hello World"
// alert( checkForPathInObject(obj,'a.success') ); // Returns false
// alert( checkForPathInObject(obj,'resTest', 'potato') ); // Returns true

ES6答案，经过彻底测试：）

const propExists = (obj, path) => {
    return !!path.split('.').reduce((obj, prop) => {
        return obj && obj[prop] ? obj[prop] : undefined;
    }, obj)
}

→请参阅具有完整测试覆盖范围的Codepen

我以以下方式使用函数。

var a = {};
a.b = {};
a.b.c = {};
a.b.c.d = "abcdabcd";

function isDefined(objectChainString) {
    try {
        var properties = objectChainString.split('.');
        var currentLevel = properties[0];
        if (currentLevel in window) {
            var consolidatedLevel = window[currentLevel];
            for (var i in properties) {
                if (i == 0) {
                    continue;
                } else {
                    consolidatedLevel = consolidatedLevel[properties[i]];
                }
            }
            if (typeof consolidatedLevel != 'undefined') {
                return true;
            } else {
                return false;
            }
        } else {
            return false;
        }
    } catch (e) {
        return false;
    }
}

// defined
console.log(checkUndefined("a.b.x.d"));
//undefined
console.log(checkUndefined("a.b.c.x"));
console.log(checkUndefined("a.b.x.d"));
console.log(checkUndefined("x.b.c.d"));