Program for removing i-th character from a string

Given a string S along with an integer i. Then your task is to remove i_th character from S.

Examples:

Input: S = Hello World!, i = 7
Output: Hello orld!
Explanation: The Xth character is W and after removing it S becomes Hello orld!

Input: S = GFG, i = 1
Output: GG
Explanation: It can be verified that after removing 1st character the string S will be GG.

Program for removing i-th character from a string using inbuilt function:

Below table represents inbuilt functions used to remove the i-th character from a string in different languages:

Language	Inbuilt Function(s)
C++	std::string::erase
Java	StringBuilder.deleteCharAt
Python	String slicing (str[:i] + str[i+1:])
C#	string.Remove
JavaScript	String slicing (str.slice(0, i) + str.slice(i+1))

Below is the implementation:

C++

//C++ code to show use of erase() function

#include <bits/stdc++.h>
using namespace std;

//Method to use erase() function
string removeCharAtIndex(string inputString, int index)
{
    //Checking for valid index and removing that portion
    if (index >= 0 && index < inputString.length()) {
        inputString.erase(index, 1);
    }
    return inputString; 
}

//Main Function
int main()
{
    //Input
    string inputString = "Hello, World!";
    int index = 7;
  
    //Function call 
    string result = removeCharAtIndex(inputString, index);
    cout << result;
    return 0;
}

Java

//Java code to show use of deleteCharAt

public class Main {
    // Method to use deleteCharAt() function
    public static String removeCharAtIndex(String inputString, int index) {
        // Checking for valid index and removing that character
        if (index >= 0 && index < inputString.length()) {
            StringBuilder sb = new StringBuilder(inputString);
            sb.deleteCharAt(index);
            return sb.toString();
        }
        return inputString;
    }

    // Main Function
    public static void main(String[] args) {
        // Input
        String inputString = "Hello, World!";
        int index = 7;

        // Function call
        String result = removeCharAtIndex(inputString, index);
        System.out.println(result);
    }
}

Python3

# Method to use erase() function
def remove_char_at_index(input_string, index):
    # Checking for valid index and removing that portion
    if 0 <= index < len(input_string):
        input_string = input_string[:index] + input_string[index+1:]
    return input_string

# Main Function
def main():
    # Input
    input_string = "Hello, World!"
    index = 7
  
    # Function call 
    result = remove_char_at_index(input_string, index)
    print(result)

if __name__ == "__main__":
    main()

C#

using System;

class Program
{
    // Method to use the RemoveAt() function
    static string RemoveCharAtIndex(string inputString, int index)
    {
        // Checking for a valid index and removing that portion
        if (index >= 0 && index < inputString.Length)
        {
            inputString = inputString.Remove(index, 1);
        }
        return inputString;
    }

    // Main Function
    static void Main()
    {
        // Input
        string inputString = "Hello, World!";
        int index = 7;

        // Function call
        string result = RemoveCharAtIndex(inputString, index);
        Console.WriteLine(result);
    }
}

// This code is contributed by shivamgupta0987654321

JavaScript

// JavaScript code to show use of slice() function

// Method to remove a character at a specific index
function removeCharAtIndex(inputString, index) {
    // Checking for a valid index and removing that character
    if (index >= 0 && index < inputString.length) {
        inputString = inputString.slice(0, index) + inputString.slice(index + 1);
    }
    return inputString;
}

// Input
let inputString = "Hello, World!";
let index = 7;

// Function call
let result = removeCharAtIndex(inputString, index);
console.log(result);

Output

Hello, orld!

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

Program for removing i-th character from a string by creating new Temporary String.

We can create a new string and add all the characters of original input string except the ith character.

Below is the implementation of the above approach:

C++

#include <bits/stdc++.h>
using namespace std;

string removeCharAtIndex(string& inputString, int index)
{
    if (index >= 0 && index < inputString.length()) {
        string result;

        // Copy characters from the original string to the
        // result string, excluding the character at the
        // specified index
        for (int i = 0; i < inputString.length(); i++) {
            if (i != index) {
                result.push_back(inputString[i]);
            }
        }

        return result;
    }
    else {
        return inputString;
    }
}

int main()
{
    // Input
    string inputString = "Hello";
    int index = 1;

    // Function_call
    string result = removeCharAtIndex(inputString, index);
    cout << result;
    return 0;
}

Java

// Java Implementation

public class RemoveCharAtIndex {

    public static String removeCharAtIndex(String inputString, int index) {
        if (index >= 0 && index < inputString.length()) {
            StringBuilder result = new StringBuilder();

            // Copy characters from the original string to the
            // result string, excluding the character at the
            // specified index
            for (int i = 0; i < inputString.length(); i++) {
                if (i != index) {
                    result.append(inputString.charAt(i));
                }
            }

            return result.toString();
        } else {
            return inputString;
        }
    }

    public static void main(String[] args) {
        // Input
        String inputString = "Hello";
        int index = 1;

        // Function call
        String result = removeCharAtIndex(inputString, index);
        System.out.println(result);
    }
}


// This code is contributed by Sakshi

Python

def removeCharAtIndex(inputString, index):
    if 0 <= index < len(inputString):
        result = ''
        # Copy characters from the original string to the
        # result string, excluding the character at the
        # specified index
        for i in range(len(inputString)):
            if i != index:
                result += inputString[i]
        return result
    else:
        return inputString

# Input
inputString = "Hello"
index = 1

# Function call
result = removeCharAtIndex(inputString, index)
print(result)

JavaScript

// JavaScript Implementation

function removeCharAtIndex(inputString, index) {
    if (index >= 0 && index < inputString.length) {
        let result = "";

        // Copy characters from the original string to the
        // result string, excluding the character at the
        // specified index
        for (let i = 0; i < inputString.length; i++) {
            if (i !== index) {
                result += inputString.charAt(i);
            }
        }

        return result;
    } else {
        return inputString;
    }
}

// Input
const inputString = "Hello";
const index = 1;

// Function call
const result = removeCharAtIndex(inputString, index);
console.log(result);

Output

Hllo

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