## C# || How To Find Largest Odd Number In String Using C#

The following is a module with functions which demonstrates how to find the largest odd number in a string using C#.

1. Largest Odd Number – Problem Statement

You are given a string num, representing a large integer. Return the largest-valued odd integer (as a string) that is a non-empty substring of num, or an empty string “” if no odd integer exists.

A substring is a contiguous sequence of characters within a string.

Example 1:

``` Input: num = "52" Output: "5" Explanation: The only non-empty substrings are "5", "2", and "52". "5" is the only odd number. ```

Example 2:

``` Input: num = "4206" Output: "" Explanation: There are no odd numbers in "4206". ```

Example 3:

``` Input: num = "35427" Output: "35427" Explanation: "35427" is already an odd number. ```

2. Largest Odd Number – Solution

The following is a solution which demonstrates how to find the largest odd number in a string.

``` 2. Largest Odd Number - Solution C# // ============================================================================ // Author: Kenneth Perkins // Date: Apr 13, 2024 // Taken From: http://programmingnotes.org/ // File: Solution.cs // Description: Demonstrates how to find largest odd number in a string // ============================================================================ public class Solution { public string LargestOddNumber(string num) { for (int index = num.Length - 1; index >= 0; --index) { if (Convert.ToInt32(num[index]) % 2 != 0) { return num.Substring(0, index + 1); } } return ""; } }// http://programmingnotes.org/ 1234567891011121314151617 // ============================================================================//    Author: Kenneth Perkins//    Date:   Apr 13, 2024//    Taken From: http://programmingnotes.org///    File:  Solution.cs//    Description: Demonstrates how to find largest odd number in a string// ============================================================================public class Solution {    public string LargestOddNumber(string num) {        for (int index = num.Length - 1; index >= 0; --index) {            if (Convert.ToInt32(num[index]) % 2 != 0) {                return num.Substring(0, index + 1);            }        }        return "";    }}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output for the example cases:

``` "5" "" "35427" ```