How To Convert String To Uppercase In C#

The string is the primitive data type in the C# language. It is widely used by programmers to develop applications. The string is commonly used to store large data. Generally, strings are used to create the user input and store the sequence of characters.

In some circumstances, it can be crucial to transform a string into uppercase characters. For instance, when a user fills out an online form, the programmer receives information in the form of a string and stores it in uppercase for sorting.

Additionally, uppercase characters are prioritized over a combination of lowercase and other characters when sorting the data.

Why Is There A Need To Convert String Into Uppercase?

While discussing “how to convert string to uppercase in C#”, this section will discuss the practical requirement for converting the string data type to uppercase characters.

1. Sorting: Characters in uppercase are sorted first. Uppercase characters are therefore given more weight.
2. Importance: Compared to other string techniques, uppercase characters are given more weight. Uppercase characters are simple to read and immediately grab the reader’s attention. They are recognized right away and given more significance.
3. Data storage: Characters are typically employed to keep track of the user’s login and other pertinent information. Prioritizing inputs and other information is a simple process.

Different Approaches To Convert String To Uppercase In C#

We’ve already discussed how translating strings into practice letters can be quite important. Several methods can be used to implement for “how to convert string to uppercase in C#”:

1. Using ToUpper() method
2. Using ToUpperInvariant() method
3. Using TextInfo.ToTitleCase() method
4. Using char.ToUpper() method

Let us now discuss the methods in brief by respective code and explanation to make us aware of “how to convert string to uppercase in C#”.

Approach 1 : Convert String To Uppercase In C# using ToUpper() method

The ToUpper() method is the pre-built method in C# programming and is commonly used to convert the string characters into uppercase. This method is concise and easy to use. This method is recommended for beginners.

Sample code :

using System;

// create a public class
public class HelloWorld
{
    public static void Main(string[] args)
    {
        // create a string
        string str = "hello world";
        
        // apply method for the conversion
        string upperStr = str.ToUpper();
        
        // print the result on the console
        Console.WriteLine (upperStr);
    }
}

Output :

HELLO WORLD

Explanation :

1. First, create a string and store some characters in it.
2. Apply the ToUpper() method to convert the string into uppercase.
3. Then, print the output on the console.

Approach 2 : Convert String To Uppercase In C# using ToUpperInvariant() method

The ToUpperInvariant() method is another approach to carry out the conversion. The syntax is the same as the previous conversion. It converts a whole string into uppercase in one take without using the loop.

Sample code :

using System;

// create a public class
public class HelloWorld
{
    public static void Main(string[] args)
    {
        // create a string
        string str = "hello world";
        
        // apply method for the conversion
        string upperStr = str.ToUpperInvariant();
        
        // print the result on the console
        Console.WriteLine (upperStr);
    }
}

Output :

HELLO WORLD

Explanation :

1. First, create a string and store some characters in it.
2. Apply the theToUpperInvariant() method to convert the string into uppercase.
3. Then, print the output on the console.

Approach 3 : Convert String To Uppercase In C# using char.ToUpper() method

The char.ToUpper() method is also applicable to carry out the conversion. But, it method converts only one character into uppercase at a time. This can be solved using the loop concept. But, this makes the code lengthier and is recommended for the beginners.

Sample code :

// import the necessary libraries
using System;

// create a public class
public class HelloWorld
{
    public static void Main(string[] args)
    {
        // create a string
        string str = "hello world";
        
        // apply the method for the conversion
        char[] chars = str.ToCharArray();
        for (int i = 0; i < chars.Length; i++)
        {
            chars[i] = char.ToUpper(chars[i]);
        }
        string upperStr = new string(chars);
        
        // print the result on the console
        Console.WriteLine (upperStr);
    }
}

Output :

HELLO WORLD

Explanation :

1. First, create a string and store some characters in it.
2. Create the object of ToCharArray().
3. Then convert whole string characters into uppercase by passing them in the method using loop.
4. Then store the uppercase characters into new string.
5. Apply the char.ToUpper() method to convert the string into uppercase.
6. Then, print the output on the console.

Best Approach for Converting String To Uppercase In C#

Our research indicates that the ToUpper() method in C# is the most effective approach for changing lowercase string characters to uppercase ones. Learn “why theToUpper() method is the best approach” for the conversion by reading this.

1. Built-in predefined function: This method is more convenient for programmers because they must use the technique directly in their code.
2. Efficiency: ToUpperCase() is an exceptionally improved and proficient strategy. It is backed by sophisticated algorithms that convert data quickly and precisely.
3. Convenient: Moreover, this method has the ability to change the entire string to uppercase. Only one character can be used in any of the other ways.

Sample Problems

Sample problem 1:

How to use the ToUpper() method in C# to convert String to uppercase.  Create a C# program that asks the user for his entire name and then uses the ToUpper() method to change the text to uppercase. Display the generated uppercase string.

Solution :

1. Take the name of the user and store it in string data type
2. Apply the ToUpper() method to convert the string into uppercase.
3. Then, print the name of the user as the output on the console.

Code :

using System;

class Program {
    static void Main(string[] args) {
        
        // get the input from the user
        Console.Write("Enter your full name: ");
        string name = Console.ReadLine();
        
        // use the method fpr the conversion
        string upperName = name.ToUpper();
        
        // print the result on the console
        Console.WriteLine("Your name in uppercase is: " + upperName);
    }
}

Output :

Enter your full name: Jugal Jangid
Your name in uppercase is: JUGAL JANGID

Sample problem 2:

How to convert from string to uppercase in C# using the toUpperInvariant() method. A teacher wanted to know the section of each student. Write a C# program that takes the input from the student and then converts the character to uppercase using the ToUpperInvariant() method. Display the resulting uppercase string to the student.

Solution :

1.	Take the section of the student and store it in string data type
2.	Apply the ToUpper() method to convert the string into uppercase.
3.	Then, print the section of the student as the output on the console.

Code :

using System;

class Program {
    static void Main(string[] args) {
        
        // get the input from the user
        Console.Write("Enter your section: ");
        
        // use the method fpr the conversion
        string section = Console.ReadLine().ToUpperInvariant();
        
        // print the result on the console
        Console.WriteLine("Your section in uppercase is: " + section);
    }
}

Output :

Enter your section: a
Your section in uppercase is: A

Sample problem 3:

How to change string to uppercase in C# using the char.ToUpper() method. Write a C# program that prompts the user to enter the initial letter of his name and then converts the character to uppercase. Display the resulting uppercase string to the user.

Solution :

1. Take the initial letter of the user name and store it in string data type
2. Apply the char.ToUpper() method to convert the string into uppercase.
3. Then, print the initial letter of the user name as the output on the console.

Code :

using System;

class Program {
    static void Main(string[] args) {
        
        // get the input from the user
        Console.Write("Enter the initial letter of your name: ");
        
        // use the method for the conversion
        char initial = Console.ReadKey().KeyChar;
        char upperInitial = char.ToUpper(initial);
        
        // print the result on the console
        Console.WriteLine("\nYour initial in uppercase is: " + upperInitial);
    }
}

Output :

Enter the initial letter of your name: d
Your initial in uppercase is: D

Conclusion

Uppercase characters are simpler to read and avoid the ambiguity generated by words that are a string of characters. As a result, programmers are regularly called upon to convert lowercase string characters to uppercase ones. One of the three procedures listed above can be used to complete this conversion.

Conversion with the ToUpper() technique is the simplest and most useful method. It is applicable to a whole string and needs fewer lines of code.