# Check if a string represents a hexadecimal number or not

Given an alphanumeric string S of length N, the task is to check if the given string represents a hexadecimal number or not. Print Yes if it represents a hexadecimal number. Otherwise, print No.

Examples:

Input: S = “BF57C”
Output: Yes
Explanation:
Decimal Representation of the given string = 783740

Input: S = “58GK”
Output: No

Approach: The approach is based on the idea that all the elements of a hexadecimal number lie between characters A to F or between integers 0 to 9. Below are the steps to solve the problem:

1. Iterate over the given string.
2. Check if each character of the string is between characters A to F or between 0 and 9.
3. If found to be true, then print Yes.
4. Otherwise, print No.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the above approach ` `#include ` `using` `namespace` `std; `   `// Function to check if the string ` `// represents a hexadecimal number ` `void` `checkHex(string s) ` `{ ` `    `  `    ``// Size of string ` `    ``int` `n = s.length(); `   `    ``// Iterate over string ` `    ``for``(``int` `i = 0; i < n; i++) ` `    ``{ ` `        ``char` `ch = s[i]; `   `        ``// Check if the character ` `        ``// is invalid ` `        ``if` `((ch < ``'0'` `|| ch > ``'9'``) && ` `            ``(ch < ``'A'` `|| ch > ``'F'``)) ` `        ``{ ` `            ``cout << ``"No"` `<< endl; ` `            ``return``; ` `        ``} ` `    ``} `   `    ``// Print true if all ` `    ``// characters are valid ` `    ``cout << ``"Yes"` `<< endl; ` `} `   `// Driver code     ` `int` `main() ` `{ ` `    `  `    ``// Given string ` `    ``string s = ``"BF57C"``; `   `    ``// Function call ` `    ``checkHex(s); `   `    ``return` `0; ` `} `   `// This code is contributed by divyeshrabadiya07`

## Java

 `// Java implementation of the above approach`   `import` `java.util.*;` `import` `java.io.*;`   `class` `GFG {`   `    ``// Function to check if the string` `    ``// represents a hexadecimal number` `    ``public` `static` `void` `checkHex(String s)` `    ``{` `        ``// Size of string` `        ``int` `n = s.length();`   `        ``// Iterate over string` `        ``for` `(``int` `i = ``0``; i < n; i++) {`   `            ``char` `ch = s.charAt(i);`   `            ``// Check if the character` `            ``// is invalid` `            ``if` `((ch < ``'0'` `|| ch > ``'9'``)` `                ``&& (ch < ``'A'` `|| ch > ``'F'``)) {`   `                ``System.out.println(``"No"``);` `                ``return``;` `            ``}` `        ``}`   `        ``// Print true if all` `        ``// characters are valid` `        ``System.out.println(``"Yes"``);` `    ``}`   `    ``// Driver Code` `    ``public` `static` `void` `main(String[] args)` `    ``{` `        ``// Given string` `        ``String s = ``"BF57C"``;`   `        ``// Function Call` `        ``checkHex(s);` `    ``}` `}`

## Python3

 `# Python3 implementation of the` `# above approach `   `# Function to check if the string` `# represents a hexadecimal number` `def` `checkHex(s):` `       `  `    ``# Size of string` `    ``n ``=` `len``(s)` ` `  `    ``# Iterate over string` `    ``for` `i ``in` `range``(n):` `        ``ch ``=` `s[i]` ` `  `        ``# Check if the character` `        ``# is invalid` `        ``if` `((ch < ``'0'` `or` `ch > ``'9'``) ``and` `            ``(ch < ``'A'` `or` `ch > ``'F'``)):` `                `  `            ``print``(``"No"``)` `            ``return` `        `  `    ``# Print true if all` `    ``# characters are valid` `    ``print``(``"Yes"``)`   `# Driver Code` `    `  `# Given string` `s ``=` `"BF57C"` ` `  `# Function call` `checkHex(s)`   `# This code is contributed by sanjoy_62`

## C#

 `// C# implementation of ` `// the above approach` `using` `System;` `class` `GFG{`   `// Function to check if the string` `// represents a hexadecimal number` `public` `static` `void` `checkHex(String s)` `{` `  ``// Size of string` `  ``int` `n = s.Length;`   `  ``// Iterate over string` `  ``for` `(``int` `i = 0; i < n; i++) ` `  ``{` `    ``char` `ch = s[i];`   `    ``// Check if the character` `    ``// is invalid` `    ``if` `((ch < ``'0'` `|| ch > ``'9'``) && ` `        ``(ch < ``'A'` `|| ch > ``'F'``)) ` `    ``{` `      ``Console.WriteLine(``"No"``);` `      ``return``;` `    ``}` `  ``}`   `  ``// Print true if all` `  ``// characters are valid` `  ``Console.WriteLine(``"Yes"``);` `}`   `// Driver Code` `public` `static` `void` `Main(String[] args)` `{` `  ``// Given string` `  ``String s = ``"BF57C"``;`   `  ``// Function Call` `  ``checkHex(s);` `}` `}`   `// This code is contributed by gauravrajput1`

Output:

```Yes

```

Time Complexity: O(N)
Auxiliary Space: O(1)

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