First uppercase letter in a string (Iterative and Recursive)

Difficulty Level : Basic
Last Updated : 18 Feb, 2021

Given a string find its first uppercase letter
Examples :

Input : geeksforgeeKs
Output : K

Input  : geekS
Output : S

Method 1: linear search
Using linear search, find the first character which is capital

C++

// C++ program to find the first
// uppercase letter using linear search
#include <bits/stdc++.h>
using namespace std;
 
// Function to find string which has
// first character of each word.
char first(string str)
{
    for (int i = 0; i < str.length(); i++)
        if (isupper(str[i]))
            return str[i];
    return 0;
}
 
// Driver code
int main()
{
    string str = "geeksforGeeKS";
    char res = first(str);
    if (res == 0)
        cout << "No uppercase letter";
    else
        cout << res << "\n";
    return 0;
}

Java

// Java program to find the first
// uppercase letter using linear search
import java.io.*;
import java.util.*;
 
class GFG {
 
    // Function to find string which has
    // first character of each word.
    static char first(String str)
    {
        for (int i = 0; i < str.length(); i++)
            if (Character.isUpperCase(str.charAt(i)))
                return str.charAt(i);
        return 0;
    }
     
    // Driver program 
    public static void main(String args[])
    {
        String str = "geeksforGeeKS";
        char res = first(str);
        if (res == 0)
            System.out.println("No uppercase letter");
        else
            System.out.println(res);
    }
}
 
 
// This code is contributed
// by Nikita Tiwari.

Python3

# Python3 program to find the first
# uppercase letter using linear search
 
# Function to find string which has
# first character of each word.
def first(str) :
     
    for i in range(0, len(str)) :
         
        if (str[i].istitle()) :
            return str[i]
             
    return 0
 
 
# Driver code
str = "geeksforGeeKS"
res = first(str)
 
if (res == 0) :
    print("No uppercase letter")
     
else :
    print(res)
     
     
# This code is contributed by Nikita Tiwari

C#

// C# program to find the first uppercase
// letter using linear search
using System;
 
class GFG {
     
    // Function to find string which has
    // first character of each word.
    static char first(string str)
    {
        for (int i = 0; i < str.Length; i++)
            if (char.IsUpper(str[i]) ) 
                return str[i];
        return '0';
    }
     
    // Driver function
    public static void Main()
    {
        string str = "geeksforGeeKS";
        char res = first(str);
        if (res == '0')
            Console.WriteLine("No uppercase"
                               + " letter");
        else
            Console.WriteLine(res);
    }
}
 
// This code is contributed by Sam007

PHP

<?php
// PHP program to find the first
// uppercase letter using linear search
 
// Function to find string which has
// first character of each word.
function first($str)
{
    for ($i = 0; $i < strlen($str); $i++)
        if (ctype_upper($str[$i]))
        {
            return $str[$i];
             
        }
    return 0;
}
 
    // Driver code
    $str = "geeksforGeeKS";
    $res = first($str);
     
    if (ord($res) ==ord(0) )
        echo "No uppercase letter";
    else
        echo $res . "\n";
 
// This code is contributed by Sam007
?>

Output:

Method 2 (Using recursion)
Recursively traverse the string and if any uppercase is found return that character

Python3

// C++ program to find the
// first uppercase letter.
#include <bits/stdc++.h>
using namespace std;
 
// Function to find string which has
// first character of each word.
char first(string str, int i=0)
{
    if (str[i] == '\0')
         return 0;
    if (isupper(str[i])) 
            return str[i];
    return first(str, i+1);
}
 
// Driver code
int main()
{
    string str = "geeksforGeeKS";
    char res = first(str);
    if (res == 0)
        cout << "No uppercase letter";
    else
        cout << res << "\n";
    return 0;
}

Java

// Java program to find the
// first uppercase letter.
import java.io.*;
 
class GFG {
     
    // Function to find string which has
    // first character of each word.
    static char first(String str, int i)
    {
        if (str.charAt(i) == '\0')
            return 0;
        if (Character.isUpperCase(str.charAt(i))) 
                return str.charAt(i);
        return first(str, i + 1);
    }
     
    // Driver code
    public static void main(String args[])
    {
        String str = "geeksforGeeKS";
        char res = first(str,0);
        if (res == 0)
            System.out.println("No uppercase letter");
        else
            System.out.println (res );
    }
}
 
// This code is contributed 
// by Nikita Tiwari.

Python 3

def capital(N, i, x):
    if i >= x:
        return -1
    elif N[i].isupper():
        return i
    if i < x:
        return capital(N, i + 1, x)
 
 
def main():
    N = input()
    N = list(N)
    x = len(N)
    y = (capital(N, 0, x))
    print(y)
 
 
if __name__ == '__main__':
    main()

C#

// C# program to find the
// first uppercase letter.
using System;
 
class GFG 
{
     
    // Function to find string 
    // which has first character
    // of each word.
    static char first(string str, int i)
    {
        if (str[i] == '\0')
            return '0';
        if (char.IsUpper(str[i]))
                return (str[i]);
        return first(str, i + 1);
    }
     
    // Driver code
    static public void Main ()
    {
        string str = "geeksforGeeKS";
        char res = first(str, 0);
        if (res == 0)
            Console.WriteLine("No uppercase letter");
        else
            Console.WriteLine(res );
    }
}
 
// This code is contributed by Anuj_67.

PHP

<?php
//PHP program to find the
// first uppercase letter.
 
// Function to find string 
// which has first character
// of each word.
 
function first($str, $i = 0)
{
    if ($str[$i] == '\0')
        return 0;
    if (ctype_upper($str[$i])) 
            return $str[$i];
    return first($str, $i+1);
}
 
// Driver code
    $str = "geeksforGeeKS";
    $res = first($str);
     
    if (ord($res) ==ord(0))
        echo "No uppercase letter";
    else
        echo $res , "\n";
 
// This code is contributed 
// by m_kit
?>

Output :

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes

Related Articles

C++

Java

Python3

C#

PHP

Python3

Java

Python 3

C#

PHP