How to create half of the string in uppercase and the other half in lowercase?

The first thing that we have to keep in my mind while solving this kind of problem is that the strings are immutable i.e,

If I am taking the following string

var string1 = "geeksforgeeks";
string1[0] = "G";
console.log(string1);

As strings are immutable, so we cannot change the character of the string, so the output of the above code will be the following.

Output:

geeksforgeeks

Approach:

There are several ways to solve this problem. Some of them are as follows.

Splitting the string into 2 different parts and changing the first part to the UPPERCASE and concatenating the new strings to get the output.
Create an empty string and add each character of the string to it using FOR loop.
Using the slicing property of strings to get the output.

Method 1: This method is implemented using 2 new variables.

Add the string into the variable.
Store the length of the string into a variable using string.length function.
Create two empty strings which are used in the future to store the newly created strings.
Use of for loops to traverse in the string.
Convert the first string to the upper case using toUpperCase().
Concatenate both of the strings to get the output.

C++

#include <iostream>

using namespace std;
 
int main() {

  string str = "geeksforgeeks",ans;

  int len = str.length();

  for(int i = 0;i<len;i++){

    if(i<=len/2){

      char a = toupper(str[i]);

      ans.push_back(a);

    }else

      ans.push_back(str[i]);

  }

  cout<<ans;

  return 0;
}
 
// This code is co ntributed by rohitsingh07052

Java

public class GFG {

    public static void main(String[] args) {

        // Input string

        String str = "geeksforgeeks";

        // StringBuilder to store the result

        StringBuilder ans = new StringBuilder();

        // Get the length of the input string

        int len = str.length();
 
        // Loop through each character in the input string

        for (int i = 0; i < len; i++) {

            // Check if the current character is in the first half of the string

            if (i <= len / 2) {

                // Convert the character to uppercase and append it to the result

                char a = Character.toUpperCase(str.charAt(i));

                ans.append(a);

            } else {

                // If the character is in the second half, just append it as is

                ans.append(str.charAt(i));

            }

        }

        // Print the final result

        System.out.println(ans);

    }
}

Python3

import math
 
string1 = 'geeksforgeeks'

string1_len = len(string1)

part_a = ''

part_b = ''
 
for i in range(int(math.ceil(string1_len // 2 + 1))):

    part_a += string1[i]
 
for i in range(int(math.ceil(string1_len // 2)) + 1, 

               string1_len):

    part_b += string1[i]
 
new_part_a = part_a.upper()
 
changed_string = new_part_a + part_b
 
print(changed_string)
 
# This code is contributed by ukasp

using System;
 
public class GFG
{

    public static void Main(string[] args)

    {

        // Input string

        string str = "geeksforgeeks";
 
        // String builder to store the result

        System.Text.StringBuilder ans = new System.Text.StringBuilder();
 
        // Get the length of the input string

        int len = str.Length;
 
        // Loop through each character in the input string

        for (int i = 0; i < len; i++)

        {

            // Check if the current character is in the first half of the string

            if (i <= len / 2)

            {

                // Convert the character to uppercase and append it to the result

                char a = char.ToUpper(str[i]);

                ans.Append(a);

            }

            else

            {

                // If the character is in the second half, just append it as is

                ans.Append(str[i]);

            }

        }
 
        // Print the final result

        Console.WriteLine(ans);

    }
}

Javascript

<script>

var string1 = 'geeksforgeeks';

var string1_len = string1.length;

var part_a = '';

var part_b = '';
 
for(var i=0 ; i<Math.ceil(string1_len/2) ; i++)
{

    part_a+=string1[i];
}
 
for(var i=Math.ceil(string1_len/2) ; i<string1_len ; i++)
{

    part_b+=string1[i];
}
 
var new_part_a = part_a.toUpperCase();
 
var changed_string = new_part_a + part_b;
 
console.log(changed_string);
</script>

Output

GEEKSFOrgeeks

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

Method 2: This method is implemented using a single new variable.

Add the string into the variable.
Store the length of the string into a variable using string.length function.
Create an empty string that is used in the future to store the newly created string.
Use of for loops to traverse the string.
Log the final string to get the output.

C++

#include <iostream>

using namespace std;
 
string convertFun(string& s1, int n)
{

    string ans = "";
 
    // Running loop on first half and making it

    // upper case

    for (int i = 0; i < n / 2; i++) {

        ans += toupper(s1[i]);

    }
 
    // Running loop on secone half

    for (int i = n / 2; i < n; i++) {

        ans += s1[i];

    }
 
    return ans;
}
 
// Driver code

int main()
{

    string s1 = "geeksforgeeks";

    // Finding length of string

    int n = s1.size();
 
    cout << convertFun(s1, n);
 
    return 0;
}
 
// This code is added by Arpit Jain

Java

public class StringConversion {

    // Function to convert the first half of the string to

    // uppercase

    static String convertFun(String s1, int n)

    {

        StringBuilder ans = new StringBuilder();
 
        // Running loop on the first half and making it

        // uppercase

        for (int i = 0; i < n / 2; i++) {

            ans.append(Character.toUpperCase(s1.charAt(i)));

        }
 
        // Running loop on the second half

        for (int i = n / 2; i < n; i++) {

            ans.append(s1.charAt(i));

        }
 
        return ans.toString();

    }
 
    // Driver code

    public static void main(String[] args)

    {

        String s1 = "geeksforgeeks";

        // Finding the length of the string

        int n = s1.length();
 
        System.out.println(convertFun(s1, n));

    }
}

Python3

import math
 
string1 = 'gfg';

string1_len = len(string1)
 
changed_string = ''
 
for i in range(math.ceil(string1_len/2)):

    changed_string += string1[i].upper();
 
for i in range(math.ceil(string1_len/2), string1_len):

    changed_string += string1[i]
 
print(changed_string)
 
# This code is contributed by avanitrachhadiya2155

using System;
 
class Program
{

    // Function to convert the first half of the string to uppercase

    static string ConvertFun(string s1, int n)

    {

        string ans = "";
 
        // Running loop on the first half and making it upper case

        for (int i = 0; i < n / 2; i++)

        {

            ans += char.ToUpper(s1[i]);

        }
 
        // Running loop on the second half

        for (int i = n / 2; i < n; i++)

        {

            ans += s1[i];

        }
 
        return ans;

    }
 
    // Driver code

    static void Main()

    {

        string s1 = "geeksforgeeks";

        // Finding the length of the string

        int n = s1.Length;
 
        Console.WriteLine(ConvertFun(s1, n));
 
        // This code is added by Arpit Jain

    }
}
 
// This code is contributed by shivamgupta310570

Javascript

<script>

var string1 = 'gfg';

var string1_len = string1.length;

var changed_string = '';
 
for(var i=0 ; i<Math.ceil(string1_len/2) ; i++)
{

    changed_string+=string1[i].toUpperCase();
}
 
for(var i=Math.ceil(string1_len/2) ; i<string1_len ; i++)
{

    changed_string+=string1[i];
}
 
console.log(changed_string);
</script>

Output

GEEKSForgeeks

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

Method 3: This method is implemented using the JavaScript Slice property.

Add the string into the variable.
Store the length of the string into a variable using string.length function.
Store the ceil value of half of the length of the string to the new variable.
Create 2 empty strings which are used in the future to store the newly created strings.
Add string to the variables using string slicing property.
Convert the first string to the upper case using toUpperCase().
Concatenate both of the strings to get the output.

C++

#include <cmath>
#include <iostream>
 
int main()
{

    // Given string

    std::string string1 = "geeks for geeks";
 
    // Calculate the length of the string

    int string1Len = string1.length();
 
    // Calculate the index to split the string into two

    // halves

    int halfString

        = static_cast<int>(std::ceil(string1Len / 2.0));
 
    // Declare variables to store the two parts of the

    // string

    std::string partA;

    std::string partB;
 
    // Extract the first half of the string

    partA = string1.substr(0, halfString);
 
    // Convert the first half to uppercase

    for (char& ch : partA) {

        ch = std::toupper(ch);

    }
 
    // Extract the second half of the string

    partB = string1.substr(halfString, string1Len);
 
    // Concatenate the modified first half and the second

    // half

    std::string changedString = partA + partB;
 
    // Print the modified string

    std::cout << changedString << std::endl;
 
    return 0;
}

Java

public class Main {

    public static void main(String[] args) {

        // Given string

        String string1 = "geeks for geeks";
 
        // Calculate the length of the string

        int string1Len = string1.length();
 
        // Calculate the index to split the string into two halves

        int halfString = (int) Math.ceil(string1Len / 2.0);
 
        // Declare variables to store the two parts of the string

        String partA;

        String partB;
 
        // Extract the first half of the string

        partA = string1.substring(0, halfString);
 
        // Convert the first half to uppercase

        String newPartA = partA.toUpperCase();
 
        // Extract the second half of the string

        partB = string1.substring(halfString, string1Len);
 
        // Concatenate the modified first half and the second half

        String changedString = newPartA + partB;
 
        // Print the modified string

        System.out.println(changedString);

    }
}

Python3

import math
 
string1 = 'geeksforgeeks'
 
string1_len = len(string1)
 
half_string = math.ceil(string1_len/2)
 
part_a = ''

part_b = ''
 
part_a = string1[:half_string]

new_part_a = part_a.upper()
 
part_b = string1[half_string:string1_len]
 
changed_string = new_part_a+part_b
 
print(changed_string)
 
# This code is contributed by rag2127

using System;
 
class Program
{

    static void Main()

    {

        // Given string

        string string1 = "geeks for geeks";
 
        // Calculate the length of the string

        int string1Len = string1.Length;
 
        // Calculate the index to split the string into two halves

        int halfString = (int)Math.Ceiling(string1Len / 2.0);
 
        // Extract the first half of the string

        string partA = string1.Substring(0, halfString);
 
        // Convert the first half to uppercase

        partA = partA.ToUpper();
 
        // Extract the second half of the string

        string partB = string1.Substring(halfString, string1Len - halfString);
 
        // Concatenate the modified first half and the second half

        string changedString = partA + partB;
 
        // Print the modified string

        Console.WriteLine(changedString);

    }
}

Javascript

<script>

var string1 = 'geeks for geeks';

var string1_len = string1.length;

var half_string = Math.ceil(string1_len/2);

var part_a;

var part_b;
 
part_a = string1.slice(0,half_string);

var new_part_a = part_a.toUpperCase();
part_b = string1.slice(half_string,string1_len);
 
var changed_string = new_part_a+part_b;
 
console.log(changed_string);
</script>