36 lines
1.6 KiB
Java
36 lines
1.6 KiB
Java
package org.usi.sq.util.numbers;
|
|
|
|
public interface INumberChecker {
|
|
/**
|
|
*
|
|
* The method takes a string as input and checks if it is a valid hexadecimal number.
|
|
* It returns a boolean value that is:
|
|
* - true, if the string is a valid hexadecimal number
|
|
* - false, if the string is not a valid hexadecimal number
|
|
*
|
|
* A valid hexadecimal number is given by a string that satisfies the following conditions:
|
|
* - the string can start with a sign (+/- are the only signs accepted as starting char)
|
|
* - the first character of a hexadecimal number is a '0'
|
|
* - the second character of a hexadecimal number is an 'x' or an 'X'
|
|
* - the following characters of a hexadecimal number are decimal digits (from 0 to 9) or
|
|
* a letter of the alphabet between 'a' and 'f' (both lowercase and uppercase letters are valid)
|
|
*
|
|
* Examples of valid hexadecimal strings:
|
|
* - +0x47f8eca1d
|
|
* - 0Xadc4790da
|
|
* - 0xAB78cd3Ab
|
|
*
|
|
* Examples of invalid hexadecimal strings:
|
|
* - +07934abc (the pattern '0x' is not respected)
|
|
* - +-0xa45cb (the string can contain only '+' or '-', but not both)
|
|
* - xabCd73aC (the pattern '0x' is not respected)
|
|
* - 0xABd19Vc ('V' is not a valid character)
|
|
*
|
|
* @param str the string that needs to be checked
|
|
* @return the boolean result of the checking, that is, true if {@code str}
|
|
* is a valid hexadecimal number and false otherwise
|
|
*
|
|
* */
|
|
boolean isHexNumber(final String str);
|
|
}
|