isIp4Address and mustBeIp4Address

small functions to check if a string is a valid ip address

small functions to check if a string is a valid ip address

isIp4Address: input is a string or char array. return value is boolean.

mustBeIp4Address: gives back true or gives an error. Like other property/function validators.

examples:

isIp4Address('123.55.2.1') => true

isIp4Address('123.455.2.1') => false

isIp4Address('hello world') => false

isIp4Address('') => false

mustBeIp4Address ... calls isIp4Address => same results, but throwing error