1 What does each piece of it represent piece is defined as t

1) What does each piece of it represent (piece is defined as that which is separated by a union or concatenation)? Explain each part in detail.

2) Overall, what application is the whole expression for?

A)

^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])$

B)

([01]?[0-9]|2[0-3]):[0-5][0-9]

Solution

1) This is a regular expression which contains various parts like \\d means a digit \'.\' means any character. [0-9] means any value between 0 to 9. () is used to make a unit.? is used after a characyylike \\d?, which means that \\d may or may not be present.