How to pass a String into a function using call by value?

In various programming languages, strings are typically passed by value, which means that the function receives a copy of the original string, and any modifications made within the function do not affect the original string. Here are the steps and functions involved in passing a string by value in C++, C#, Python, JavaScript, and Java:

Steps to pass a String into a function using call by value in C++

1. Define a function that takes a string as a parameter.
2. The function receives a copy of the original string, which is a local copy within the function.
3. Any modifications made to the string within the function do not affect the original string.

Below is the implementation in C++:

C++

#include <iostream>
#include <string>

void modifyString(std::string str)
{
    str = "Modified string";
}

int main()
{
    std::string myString = "Original string";
    modifyString(myString);

    std::cout << myString
              << std::endl; // Output: "Original string"

    return 0;
}

Output

Original string

Steps to pass a String into a function using call by value in C#

1. Define a function that takes a string as a parameter.
2. The function receives a copy of the original string, which is a local copy within the function.
3. Any modifications made to the string within the function do not affect the original string.

Below is the implementation in C#:

C#

using System;

class Program {
    static void ModifyString(string str) {
        str = "Modified string";
    }

    static void Main() {
        string myString = "Original string";
        ModifyString(myString);

        Console.WriteLine(myString); // Output: "Original string"
    }
}

Output

Original string

Steps to pass a String into a function using call by value in Python

1. Define a function that takes a string as a parameter.
2. The function receives a copy of the original string, which is a local copy within the function.
3. Any modifications made to the string within the function do not affect the original string.

Below is the implementation in Python:

Python3

def modify_string(str):
    str = "Modified string"

my_string = "Original string"
modify_string(my_string)

print(my_string)  # Output: "Original string"

Output

Original string

Steps to pass a String into a function using call by value in JavaScript

1. Define a function that takes a string as a parameter.
2. The function receives a copy of the original string, which is a local copy within the function.
3. Any modifications made to the string within the function do not affect the original string.

Below is the implementation in Javascript:

Javascript

function modifyString(str) {
    str = "Modified string";
}

let myString = "Original string";
modifyString(myString);

console.log(myString); // Output: "Original string"

Output

Original string

Steps to pass a String into a function using call by value in Java

1. Define a function that takes a string as a parameter.
2. The function receives a copy of the original string, which is a local copy within the function.
3. Any modifications made to the string within the function do not affect the original string.

Below is the implementation in Java:

Java

public class StringModificationExample {
    static void modifyString(String str) {
        str = "Modified string";
    }

    public static void main(String[] args) {
        String myString = "Original string";
        modifyString(myString);

        System.out.println(myString); // Output: "Original string"
    }
}

Output

Original string

Conclusion:

In each of these programming languages, you pass a string by value, which means that the function works with a copy of the original string, and any changes made within the function do not impact the original string.