Regular Expressions to Validate ISBN Code
Given some ISBN Codes, the task is to check if they are valid or not using regular expressions. Rules for the valid codes are:
- It is a unique 10 or 13-digit.
- It may or may not contain a hyphen.
- It should not contain whitespaces and other special characters.
- It does not allow alphabet letters.
Examples:
Input: str = ”978-1-45678-123-4?
Output: True
Input: str = ”ISBN446877428FCI?
Output: False
Explanation: It should contain digits and hyphens only.
Approach: The problem can be solved based on the following idea:
Create a regex pattern to validate the number as written below:
regex = “^(?=(?:[^0-9]*[0-9]){10}(?:(?:[^0-9]*[0-9]){3})?$)[\\d-]+$“
Where,
- ^: Represents the beginning of the string.
- ?: Either it contains or not.
- $: Ending of the string.
- *: Match preceding expression zero or more times
- {n}: Match preceding expression exactly n times
Follow the below steps to implement the idea:
- Create a regex expression for ISBN Codes.
- Use Pattern class to compile the regex formed.
- Use the matcher function to check whether the ISBN Code is valid or not.
- If it is valid, return true. Otherwise, return false.
Below is the implementation of the above approach.
Java
import java.util.regex.*;
class GFG {
public static boolean isValidISBNCode(String str)
{
String regex
= "^(?=(?:[^0-9]*[0-9]){10}(?:(?:[^0-9]*[0-9]){3})?$)[\\d-]+$" ;
Pattern p = Pattern.compile(regex);
if (str == null ) {
return false ;
}
Matcher m = p.matcher(str);
return m.matches();
}
public static void main(String args[])
{
String str1 = "978-1-45678-123-4" ;
System.out.println(isValidISBNCode(str1));
String str2 = "1-56619-909-3" ;
System.out.println(isValidISBNCode(str2));
String str3 = "1207199818865" ;
System.out.println(isValidISBNCode(str3));
String str4 = "978-1-12345-909-4 2" ;
System.out.println(isValidISBNCode(str4));
String str5 = "ISBN446877428FCI" ;
System.out.println(isValidISBNCode(str5));
}
}
|
C++
#include <iostream>
#include <regex>
using namespace std;
bool isValidISBNCode(string str)
{
const regex pattern( "^(?=(?:[^0-9]*[0-9]){10}(?:(?:[^0-"
"9]*[0-9]){3})?$)[\\d-]+$" );
if (str.empty()) {
return false ;
}
if (regex_match(str, pattern)) {
return true ;
}
else {
return false ;
}
}
int main()
{
string str1 = "978-1-45678-123-4" ;
cout << isValidISBNCode(str1) << endl;
string str2 = "1-56619-909-3" ;
cout << isValidISBNCode(str2) << endl;
string str3 = "1207199818865" ;
cout << isValidISBNCode(str3) << endl;
string str4 = "978-1-12345-909-4 2" ;
cout << isValidISBNCode(str4) << endl;
string str5 = "ISBN446877428FCI" ;
cout << isValidISBNCode(str5) << endl;
return 0;
}
|
Python3
import re
def isValidISBNCode( str ):
regex = "^(?=(?:[^0-9]*[0-9]){10}(?:(?:[^0-9]*[0-9]){3})?$)[\\d-]+$"
p = re. compile (regex)
if ( str = = None ):
return False
if (re.search(p, str )):
return True
else :
return False
str1 = "978-1-45678-123-4"
print (isValidISBNCode(str1))
str2 = "1-56619-909-3"
print (isValidISBNCode(str2))
str3 = "1207199818865"
print (isValidISBNCode(str3))
str4 = "978-1-12345-909-4 2"
print (isValidISBNCode(str4))
str5 = "ISBN446877428FCI"
print (isValidISBNCode(str5))
|
C#
using System;
using System.Text.RegularExpressions;
class GFG {
static void Main( string [] args)
{
string [] str
= { "978-1-45678-123-4" , "1-56619-909-3" ,
"1207199818865" , "978-1-12345-909-4 2" ,
"ISBN446877428FCI" };
foreach ( string s in str)
{
Console.WriteLine(isValidISBNCode(s) ? "true"
: "false" );
}
Console.ReadKey();
}
public static bool isValidISBNCode( string str)
{
string strRegex
= @"^(?=(?:[^0-9]*[0-9]){10}(?:(?:[^0-9]*[0-9]){3})?$)[\d-]+$" ;
Regex re = new Regex(strRegex);
if (re.IsMatch(str))
return ( true );
else
return ( false );
}
}
|
Javascript
function isValidISBNCode(str) {
let regex = new RegExp(/^(?=(?:[^0-9]*[0-9]){10}(?:(?:[^0-9]*[0-9]){3})?$)[\d-]+$/);
if (str == null ) {
return "false" ;
}
if (regex.test(str) == true ) {
return "true" ;
}
else {
return "false" ;
}
}
let str1 = "978-1-45678-123-4" ;
console.log(isValidISBNCode(str1));
let str2 = "1-56619-909-3" ;
console.log(isValidISBNCode(str2));
let str3 = "1207199818865" ;
console.log(isValidISBNCode(str3));
let str4 = "978-1-12345-909-4 2" ;
console.log(isValidISBNCode(str4));
let str5 = "ISBN446877428FCI" ;
console.log(isValidISBNCode(str5));
|
Output
true
true
true
false
false
Time Complexity: O(N) for each test case, where N is the length of the given string.
Auxiliary Space: O(1)
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Last Updated :
24 Feb, 2023
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