isEmpty is a compilation of functions to check if is a empty value on javascript compatible with ECMA5+

isEmpty.js

/**
*
*   boolean isEmpty ( value )
*
*   Example:
*
*   var a = null;
*   if (isEmpty(a)) {
*       alert ('empty variable');
*   }
*/
function isEmpty (value) {
    if (value == null || value == undefined) {
        return true;
    }
    if (value.prop && value.prop.constructor === Array) {
        return value.length == 0;
    }
    else if (typeof value == 'object') {
        return Object.keys(value).length === 0 && value.constructor === Object
    }
    else if (typeof value == 'string') {
        return value.length == 0;
    }
    else if (typeof value == 'number') {
        return value == 0;
    } else if (!value) {
        return true;
    }
    return false;
}

/**
*
*   Example:
*
*   var a = "";
*   if (a.isEmpty()) {
*       alert ('empty string');
*   }
*/
String.prototype.isEmpty = function() {
    return this.toString().length == 0;
};
/**
*
* Example:
*
*   var a = 1;
*   if (a.isEmpty()) {
*       alert ('empty number');
*   }
*
*   Note:
*
*   Use only with variable.
*/
Number.prototype.isEmpty = function() {
    return this === 0;
};
/**
*
*   Example:
*
*   var a = [];
*   if (a.isEmpty()) {
*       alert ('empty array');
*   }
*/
Array.prototype.isEmpty = function() {
    return this.length == 0;
};
/**
*
*   Example:
*
*   var a = {};
*   if (a.isEmpty()) {
*       alert ('empty object');
*   }
*
*   Note:
*   Dont work with null value.
*/
Object.prototype.isEmpty = function() {
    return Object.keys(this).length === 0 && this.constructor === Object;
};

"Object.prototype.isEmpty" kills Object as hash abilities

@tesmen can you give me an example or log 😄
thanks!