Fixed.

Done.

Done.

It's acceptable for such small arrays.

TDD for JS:

describe("Testing some IP addresses", function(){

  it("Testing valid IPs", function(){
    Test.assertEquals(isValidIP("1.2.3.4"), true, "1.2.3.4 must be valid IP address");
    Test.assertEquals(isValidIP("123.45.67.89"), true, "123.45.67.89 must be valid IP address");
  });
  it("Testing invalid IPs", function(){
    Test.assertEquals(isValidIP("1.2.3"), false, "1.2.3 must be invalid IP address");
    Test.assertEquals(isValidIP("1.2.3.4.5"), false, "1.2.3.4.5 must be invalid IP address");
    Test.assertEquals(isValidIP("123.456.78.90"), false, "123.456.78.90 must be invalid IP address");
    Test.assertEquals(isValidIP("123.045.067.089"), false, "123.045.067.089 must be invalid IP address");
  });
});

I see, thanks for reply.

It's strange value. But anyway I suggest to describe this issue in the description.

Input data:
[ { firstName: 'John', lastName: 'Doe' },
{ firstName: 'Richard', lastName: 'Roe' } ].

The function has to return 'John,Doe,Richard,Roe' or not?