Represent Int64 as a Binary string in C#

To represent Int64 as a binary string in C#, use the Convert.ToString() method with base 2 as the second parameter. Int64 represents a 64-bit signed integer that can hold values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

Syntax

Following is the syntax for converting Int64 to binary string −

Convert.ToString(longValue, 2)

Parameters

• longValue − The Int64 value to convert
• 2 − The base for binary representation

Return Value

Returns a string representation of the Int64 value in binary format (base 2).

Using Convert.ToString() for Binary Conversion

Example

using System;

class Demo {
    static void Main() {
        long val = 753458;
        Console.WriteLine("Long: " + val);
        Console.WriteLine("Binary String: " + Convert.ToString(val, 2));
    }
}

The output of the above code is −

Long: 753458
Binary String: 10110111111100110010

Converting Multiple Int64 Values

Example

using System;

class Program {
    static void Main() {
        long[] values = {0, 1, 15, 255, 1024, 753458, 9223372036854775807};
        
        Console.WriteLine("Int64 to Binary Conversion:");
        Console.WriteLine("---------------------------");
        
        foreach(long val in values) {
            string binary = Convert.ToString(val, 2);
            Console.WriteLine($"Decimal: {val,20} | Binary: {binary}");
        }
    }
}

The output of the above code is −

Int64 to Binary Conversion:
---------------------------
Decimal:                    0 | Binary: 0
Decimal:                    1 | Binary: 1
Decimal:                   15 | Binary: 1111
Decimal:                  255 | Binary: 11111111
Decimal:                 1024 | Binary: 10000000000
Decimal:               753458 | Binary: 10110111111100110010
Decimal:  9223372036854775807 | Binary: 111111111111111111111111111111111111111111111111111111111111111

Handling Negative Int64 Values

Example

using System;

class Program {
    static void Main() {
        long positiveVal = 753458;
        long negativeVal = -753458;
        
        Console.WriteLine("Positive Value: " + positiveVal);
        Console.WriteLine("Binary: " + Convert.ToString(positiveVal, 2));
        Console.WriteLine();
        
        Console.WriteLine("Negative Value: " + negativeVal);
        Console.WriteLine("Binary: " + Convert.ToString(negativeVal, 2));
    }
}

The output of the above code is −

Positive Value: 753458
Binary: 10110111111100110010

Negative Value: -753458
Binary: 1111111111111111111111111110100100000010000001101110

Conclusion

The Convert.ToString() method with base 2 effectively converts Int64 values to their binary string representation. This method handles both positive and negative values, with negative values represented using two's complement notation in the binary output.