Object.defineProperty(Object.prototype, 'safeGet', { 

  enumerable: false,

  writable: false,

  value: function(p) {

    if (!p) throw new Error('[safeGet] empty value!');

    return p.split('.').reduce((acc, k) => {

      if (acc && k in acc) return acc[k];

      return undefined;

    }, this);

  }

});

​

// Object to test on

let test = { 

  a: { 

    b: 'b property value',

    c: { }

  } 

}

​

console.log(`Note that 'Object.safeGet' is not enumerable and will not break existing loops:`)

for(prop in test)

  console.log(`Found prop: ${prop}`);

​

console.log(`Test known property access: ${test.safeGet('a')}`);

console.log(`Test known sub property access: ${test.safeGet('a.b')}`);

console.log(`Test unknown sub property access: ${test.safeGet('a.c.d.e')}`);

console.log('---------------------------------------------------');

console.log(`Passing an empty value will throw an exception:`);

test.safeGet();