Sabari M
Updated date Jan 10, 2023
In this blog, we will learn how to convert a string to an Integer in C#

In C#, We can easily convert a string to an integer in multiple ways as mentioned below,

• Using `Int32.Parse()` method
• Using `Int32.TryParse()` method
• Using `Convert.ToInt32()` method

## Using `Int32.Parse()` method

`Int32.Parse()` method is used to convert a string to an integer in C#. We will use `Int32 `or `int `to parse the string.

``````using System;

namespace ConvertStringToInt
{
class Program
{
public static void Main()
{
string Numstr = "75";
// Parse() method is used to convert a string to an integer
int num = Int32.Parse(Numstr);
// OR
//int num = int.Parse(Numstr);

Console.WriteLine(num);

}
}
}
``````

### Output:

``75``

If in case of conversion failure, the Parse method will return `FormatException`. We will use `try...catch` block to handle this exception.

``````using System;

namespace ConvertStringToInt
{
class Program
{
public static void Main()
{
string Numstr = "75abc";   // Invalid input

try
{
int num = Int32.Parse(Numstr);
Console.WriteLine(num);
}
catch (FormatException)
{
Console.WriteLine("Invalid input");
}

}
}
}
``````

### Output:

``Invalid input``

## Using `Int32.TryParse()` method

`Int32.TryParse()` method is used to convert a string into an integer. If the conversion is successful then it returns true otherwise returns false.

``````using System;

namespace ConvertStringToInt
{
class Program
{
public static void Main()
{
string Numstr = "75";

// This method returns true if success
bool success = Int32.TryParse(Numstr, out int num);
// OR
//bool success = int.TryParse(Numstr, out int num);

if (success)
Console.WriteLine(num);
else
Console.WriteLine("Invalid input.");

}
}
}
``````

### Output:

``75``

## Using `Convert.ToInt32()` method

`Convert.ToInt32()` method is also doing the same job as the above methods do as shown below,

``````using System;

namespace ConvertStringToInt
{
class Program
{
public static void Main()
{
string NumStr = "101";

// ToInt32 method converts a string to an integer
int num = Convert.ToInt32(NumStr);
Console.WriteLine(num);
}
}
}
``````

### Output:

``101``

If the conversion fails, the `ToInt32 `method returns the FormatException. We will use `try..catch` block to handle the exception.