# Program to check valid mobile number

• Difficulty Level : Medium
• Last Updated : 26 Dec, 2022

Mobile Number validation criteria:

• The first digit should contain numbers between 6 to 9.
• The rest 9 digit can contain any number between 0 to 9.
• The mobile number can have 11 digits also by including 0 at the starting.
• The mobile number can be of 12 digits also by including 91 at the starting

The number which satisfies the above criteria is a valid mobile Number.

Examples:

```Input : Enter Mobile Number:
7873923408
Output :Valid Mobile Number

Input : Enter Mobile Number:
5678729234
Output :Invalid Mobile Number```

Prerequisites: Java Regular Expressions

## C++

 `// C++ program to check if given mobile number` `// is valid.` `#include ` `#include ` `using` `namespace` `std;`   `bool` `isValid(string s)` `{` `    ``// The given argument to pattern()` `    ``// is regular expression. With the help of` `    ``// regular expression we can validate mobile` `    ``// number.` `    ``// 1) Begins with 0 or 91` `    ``// 2) Then contains 6,7 or 8 or 9.` `    ``// 3) Then contains 9 digits` `  ``const` `regex pattern(``"(0|91)?[6-9][0-9]{9}"``);`   `  ``// regex_match() is used to` `  ``// to find match between given number` `  ``// and regular expression` `  ``if``(regex_match(s, pattern))` `  ``{` `    ``return` `true``;` `  ``}` `  ``else` `  ``{` `    ``return` `false``;` `  ``}` `}`   `// Driver Code` `int` `main()` `{` `  ``string s = ``"347873923408"``;` `  ``if``(isValid(s))` `  ``{` `      ``cout << ``"Valid"``;` `  ``}` `  ``else` `  ``{` `      ``cout<<``"Invalid"``;` `  ``}` `  ``return` `0;` `}`   `// This code is contributed by yuvraj_chandra`

## Java

 `// Java program to check if given mobile number` `// is valid.` `import` `java.util.regex.*;` `import` `java.util.Scanner;`   `class` `GFG{` `    `  `public` `static` `boolean` `isValid(String s)` `{` `    `  `    ``// The given argument to compile() method ` `    ``// is regular expression. With the help of ` `    ``// regular expression we can validate mobile` `    ``// number. ` `    ``// 1) Begins with 0 or 91` `    ``// 2) Then contains 6,7 or 8 or 9.` `    ``// 3) Then contains 9 digits` `    ``Pattern p = Pattern.compile(``"(0|91)?[6-9][0-9]{9}"``);`   `    ``// Pattern class contains matcher() method` `    ``// to find matching between given number ` `    ``// and regular expression` `    ``Matcher m = p.matcher(s);` `    ``return` `(m.find() && m.group().equals(s));` `}`   `// Driver code` `public` `static` `void` `main(String[] args)` `{` `    ``String s = ``"347873923408"``;` `    `  `    ``if` `(isValid(s)) ` `        ``System.out.println(``"Valid Number"``);     ` `    ``else` `        ``System.out.println(``"Invalid Number"``);     ` `}` `}`

## Python

 `# Python program to check if ` `# given mobile number is valid` `import` `re`   `def` `isValid(s):` `    `  `    ``# 1) Begins with 0 or 91` `    ``# 2) Then contains 6,7 or 8 or 9.` `    ``# 3) Then contains 9 digits` `    ``Pattern ``=` `re.``compile``(``"(0|91)?[6-9][0-9]{9}"``)` `    ``return` `Pattern.match(s)`   `# Driver Code` `s ``=` `"347873923408"` `if` `(isValid(s)): ` `    ``print` `(``"Valid Number"``)     ` `else` `:` `    ``print` `(``"Invalid Number"``) `     `# This code is contributed by rishabh_jain `

## C#

 `// C# program to validate the Mobile` `// Number using Regular Expressions` `using` `System;` `using` `System.Text.RegularExpressions;`   `class` `GFG {` `    ``// Main Method` `    ``static` `void` `Main(``string``[] args)` `    ``{` `        ``// Input strings to Match` `        ``// valid mobile number` `        ``string` `str = ``"347873923408"``;` `        ``if` `(isValid(str)) {` `            ``Console.WriteLine(``"Valid Number"``);` `        ``}` `        ``else` `{` `            ``Console.WriteLine(``"Invalid Number"``);` `        ``}` `    ``}`   `    ``// method containing the regex` `    ``public` `static` `bool` `isValid(``string` `str)` `    ``{` `        ``string` `strRegex = ``@"^(0|91)?[6-9][0-9]{9}\$"``;` `        ``Regex re = ``new` `Regex(strRegex);` `        ``if` `(re.IsMatch(str))` `            ``return` `(``true``);` `        ``else` `            ``return` `(``false``);` `    ``}` `}` `//This code is contributed by Rahul Chauhan`

## Javascript

 `// Javascript program to check` `// valid Mobile Number`   `// Function to validate the` `// Mobile Number  ` `function` `isValid_Mobile_Number(mobile_number) {` `    ``// Regex to check valid` `    ``// mobile_number  ` `    ``let regex = ``new` `RegExp(/(0|91)?[6-9][0-9]{9}/);`   `    ``// if mobile_number ` `    ``// is empty return false` `    ``if` `(mobile_number == ``null``) {` `        ``return` `"false"``;` `    ``}`   `    ``// Return true if the mobile_number` `    ``// matched the ReGex` `    ``if` `(regex.test(mobile_number) == ``true``) {` `        ``return` `"true"``;` `    ``}` `    ``else` `{` `        ``return` `"false"``;` `    ``}` `}`   `// Driver Code` `// Test Case 1:` `let str1 = ``"9136812895"``;` `console.log(isValid_Mobile_Number(str1));`   `// Test Case 2:` `let str2 = ``"7873923408"``;` `console.log(isValid_Mobile_Number(str2));`   `// Test Case 3:` `let str3 = ``"5678729234"``;` `console.log(isValid_Mobile_Number(str3));`   `// Test Case 4:` `let str4 = ``"09793295673"``;` `console.log(isValid_Mobile_Number(str4));`     `// This code is contributed by Rahul Chauhan`

Output:

`Invalid Number`

Time Complexity: O(N) where N is the length of the given string.
Auxiliary Space: O(1)

My Personal Notes arrow_drop_up
Related Articles