Given a string s, the task is to convert the first letter of each word in the string to uppercase.
Note: Letters other than the first one must be converted to lowercase.
Examples:
Input: s = "gEEKs"
Output: "Geeks"
Explanation: Given string s contains only single word "gEEKs". The first letter is converted to the uppercase and the rest to the lowercase.Input: s = "i love programming"
Output: "I Love Programming"
Explanation: Given string s contains three words "i", "love" and "programming". The first letter of each word is converted to uppercase and the other to lowercase.
Try It Yourself
Table of Content
Using Inbuilt method - O(n) Time and O(n) Space
Various programming languages provide different inbuilt methods and functions to convert a character to lowercase or uppercase accordingly.
// C++ Program to convert first character
// of word in a string to uppercase
#include <bits/stdc++.h>
using namespace std;
// Function to convert first character
// of word in a string to uppercase
string convert(string s) {
// Create a char array of given String
stringstream str(s);
string word;
string result = "";
// Declare a character of space
// To identify that the next character is the starting
// of a new word
while (str >> word) {
word[0] = toupper(word[0]);
result.append(word);
result.append(" ");
}
// remove the extra space at end of string
result.pop_back();
return result;
}
int main() {
string s = "gEEks fOr GeeKs";
// Convert that string into lowercase
transform(s.begin(), s.end(), s.begin(), ::tolower);
cout << convert(s);
return 0;
}
// C Program to convert first character
// of word in a string to uppercase
#include <ctype.h>
#include <stdio.h>
#include <string.h>
void convert(char *s) {
int len = strlen(s);
char result[len + 1];
for (int i = 0; i < len; i++) {
// If first character of a word is found
if ((s[i] != ' ') && (i == 0 || s[i - 1] == ' ')) {
// Convert into Upper-case
result[i] = toupper(s[i]);
}
else {
result[i] = s[i];
}
}
result[len] = '\0';
printf("%s\n", result);
}
int main() {
char s[] = "gEEks fOr GeeKs";
// Convert that string into lowercase
for (int i = 0; s[i] != '\0'; i++) {
s[i] = tolower(s[i]);
}
convert(s);
return 0;
}
// Java Program to convert first character
// of word in a string to uppercase
class GfG {
// Function to convert first character
// of word in a string to uppercase
static String convert(String s) {
StringBuffer str = new StringBuffer();
// Declare a character of space
// To identify that the next character is the
// starting of a new word
char ch = ' ';
for (int i = 0; i < s.length(); i++) {
// If previous character is space and current
// character is not space then it shows that
// current letter is the starting of the word
if (ch == ' ' && s.charAt(i) != ' ')
str.append(
Character.toUpperCase(s.charAt(i)));
else
str.append(s.charAt(i));
ch = s.charAt(i);
}
// Return the string with trimming
return str.toString().trim();
}
public static void main(String args[]) {
String s = "gEEks fOr GeeKs";
// Convert that string into lowercase
s = s.toLowerCase();
System.out.println(convert(s));
}
}
# Python Program to convert first character
# of word in a string to uppercase
import string
import io
# Function to convert first character
# of word in a string to uppercase
def convert(s):
# Create a stream from the string
s = io.StringIO(s)
result = ""
# Declare a character of space
# To identify that the next character is the starting
# of a new word
for word in s.read().split():
# Convert that string into lowercase
word = word.lower()
# capitalize() convert first character
# of word to uppercase
word = word.capitalize()
# append the word in result
result = " ".join([result,word])
# Return the string with trimming
return result.strip()
if __name__ == "__main__":
s1 = "gEEks fOr GeeKs"
print(convert(s1))
// C# Program to convert first character
// of word in a string to uppercase
using System;
class GfG {
// Function to convert first character
// of word in a string to uppercase
static string convert(string s) {
// Declare a character of space
// To identify that the next character is the
// starting of a new word
char ch = ' ';
string result = "";
for (int i = 0; i < s.Length; i++) {
// If previous character is space and current
// character is not space then it shows that
// current letter is the starting of the word
if (ch == ' ' && s[i] != ' ') {
result = string.Concat(result,char.ToUpper(s[i]));
}
else
result = string.Concat(result,s[i]);
ch = s[i];
}
return result.Trim();
}
static void Main(string[] args) {
string s = "gEEks fOr GeeKs";
// Convert that string into lowercase
s = s.ToLower();
Console.WriteLine(convert(s));
}
}
// Javascript Program to convert first character
// of word in a string to uppercase
function convert(s) {
// Declare a character of space
// To identify that the next character is the
// starting of a new word
let result = "";
let ch = " ";
for (let i = 0; i < s.length; i++) {
// If previous character is space and current
// character is not space then it shows that
// current letter is the starting of the word
if (ch === " " && s.charAt(i) !== " ") {
result = result.concat(s.charAt(i).toUpperCase());
}
else {
result = result.concat(s.charAt(i));
}
ch = s.charAt(i);
}
// Return the string with trimming
return result.trim();
}
let s = "gEEks fOr GeeKs";
// Convert that string into lowercase
s = s.toLowerCase();
console.log(convert(s));
Output
Geeks For Geeks
Iterative Method - O(n) Time and O(1) Space
The first letter of the string and the letter after space ' ' character marks the beginning of the new word, the idea is to convert this letter to the uppercase and all the remaining letters before the next space ' ' or end of string to the lowercase. To do so, the ASCII Value of the characters need to be manipulated. If the character is a lowercase letter, we can convert it to uppercase using the ASCII value manipulation and vice-versa.
// C++ Program to convert first character
// of word in a string to uppercase
#include <bits/stdc++.h>
using namespace std;
// Function to convert first character
// of word in a string to uppercase
string convert(string s) {
for (int i = 0; i < s.length(); i++) {
// If first character of a
// word is found
if ((s[i] != ' ') && (i == 0 || s[i - 1] == ' ')) {
// If it is in lower-case
// Convert into Upper-case
if (s[i] >= 'a' && s[i] <= 'z') {
s[i] = (char)(s[i] - 'a' + 'A');
}
}
// If apart from first character
// Any one is in Upper-case
else if (s[i] >= 'A' && s[i] <= 'Z') {
// Convert into Lower-Case
s[i] = (char)(s[i] + 'a' - 'A');
}
}
return s;
}
int main() {
string s = "gEEks fOr GeeKs";
cout<<convert(s);
return 0;
}
// C Program to convert first character
// of word in a string to uppercase
#include <stdio.h>
#include <ctype.h>
// Function to convert first character
// of word in a string to uppercase
void convert(char *s) {
for (int i = 0; s[i] != '\0'; i++) {
// If first character of a word is found
if ((s[i] != ' ') && (i == 0 || s[i - 1] == ' ')) {
// If it is in lower-case
// Convert into Upper-case
if (s[i] >= 'a' && s[i] <= 'z') {
s[i] = s[i] - 'a' + 'A';
}
}
// If apart from first character
// Any one is in Upper-case
else if (s[i] >= 'A' && s[i] <= 'Z') {
// Convert into Lower-Case
s[i] = s[i] + 'a' - 'A';
}
}
}
int main() {
char s[] = "gEEks fOr GeeKs";
convert(s);
printf("%s", s);
return 0;
}
// Java Program to convert first character
// of word in a string to uppercase
class GfG {
static String convert(String s){
// Create a char array of given String
char str[] = s.toCharArray();
for (int i = 0; i < s.length(); i++) {
// If first character of a word is found
if ((str[i] != ' ') && (i == 0 || str[i - 1] == ' ')) {
// If it is in lower-case
// Convert into Upper-case
if (str[i] >= 'a' && str[i] <= 'z') {
str[i] = (char)(str[i] - 'a' + 'A');
}
}
// If apart from first character
// Any one is in Upper-case
else if (str[i] >= 'A' && str[i] <= 'Z')
// Convert into Lower-Case
str[i] = (char)(str[i] + 'a' - 'A');
}
// Convert the char array to equivalent String
String res = new String(str);
return res;
}
public static void main(String[] args) {
String s = "gEEks fOr GeeKs";
System.out.println(convert(s));
}
}
# Program to convert first character
# of word in a string to uppercase
def convert(s):
str = list(s)
for i in range(len(s)):
# If first character of a word is found
if (str[i] != ' ') and (i == 0 or s[i-1] == ' '):
# If it is in lower-case
# Convert into Upper-case
if (str[i] >= 'a' and str[i] <= 'z'):
str[i] = chr(ord(str[i]) - ord('a') + ord('A'))
# If apart from first character
# Any one is in Upper-case
elif (str[i] >= 'A' and str[i] <= 'Z'):
# Convert into Lower-Case
str[i] = chr(ord(str[i]) + ord('a') - ord('A'))
# Convert the char array
# to equivalent string
res = "".join(str)
return res
if __name__ == "__main__":
s = "gEEks fOr GeeKs"
print(convert(s))
// C# program to convert first character
// uppercase in a sentence
using System;
class GfG {
static String convert(String s) {
// Create a char array of
// given String
char []str = s.ToCharArray();
for (int i = 0; i < s.Length; i++) {
// If first character of a
// word is found
if ((s[i] != ' ') && (i == 0 || s[i - 1] == ' ')) {
// If it is in lower-case
// Convert into Upper-case
if (str[i] >= 'a' && str[i] <= 'z') {
str[i] = (char)(str[i] - 'a' + 'A');
}
}
// If apart from first character
// Any one is in Upper-case
else if (str[i] >= 'A' && str[i] <= 'Z')
// Convert into Lower-Case
str[i] = (char)(str[i] + 'a' - 'A');
}
// Convert the char array to
// equivalent String
String res = new String(str);
return res;
}
static void Main() {
String str = "gEEks fOr GeeKs";
Console.Write(convert(str));
}
}
// Javascript program to convert first character
// of word in a string to uppercase
function convert(s) {
// Create a char array of given String
let ch = s.split("");
for (let i = 0; i < s.length; i++) {
// If first character of a word is found
if ((s[i] != ' ') && (i == 0 || s[i - 1] == ' ')) {
// If it is in lower-case
// Convert into Upper-case
if (ch[i] >= 'a' && ch[i] <= 'z') {
ch[i] = String.fromCharCode(ch[i].charCodeAt(0) -
'a'.charCodeAt(0) + 'A'.charCodeAt(0));
}
}
// If apart from first character
// Any one is in Upper-case
else if (ch[i] >= 'A' && ch[i] <= 'Z')
// Convert into Lower-Case
ch[i] = String.fromCharCode(ch[i].charCodeAt(0) +
'a'.charCodeAt(0) - 'A'.charCodeAt(0));
}
// Convert the char array to equivalent String
let st = (ch).join("");
return st;
}
let s = "gEEks fOr GeeKs";
console.log(convert(s));
Output
Geeks For Geeks