Object has-property-deep check in JavaScript

Question

Let\'s say we have this JavaScript object:

var object = {
   innerObject:{
       deepObject:{
           value:\'Here am I\'
       }
   }
};

<

Answer 1

There isn't a built-in way for this kind of check, but you can implement it easily. Create a function, pass a string representing the property path, split the path by ., and iterate over this path:

Object.prototype.hasOwnNestedProperty = function(propertyPath){
    if(!propertyPath)
        return false;

    var properties = propertyPath.split('.');
    var obj = this;

    for (var i = 0; i < properties.length; i++) {
        var prop = properties[i];

        if(!obj || !obj.hasOwnProperty(prop)){
            return false;
        } else {
            obj = obj[prop];
        }
    }

    return true;
};

// Usage:
var obj = {
   innerObject:{
       deepObject:{
           value:'Here am I'
       }
   }
}

obj.hasOwnNestedProperty('innerObject.deepObject.value');