Convert char array, string

A char array can be converted into a string. The syntax to perform this conversion can be confusing at first. The simplest approach uses the string constructor.

For string conversions, we can use the C# string constructor. The StringBuilder class can also be used—but it is not ideal for this purpose.

First example

Here we convert the char array. This approach is interesting because you see the lowercase string type has a constructor. Things like ints do not have constructors.

using System;

// Create 3-character array.
char[] array = new char[3];
array[0] = 'c';
array[1] = 'a';
array[2] = 't';

// Create string from array.
string result = new string(array);
Console.WriteLine($"STRING: {result}");
STRING: cat

StringBuilder

Here we use the StringBuilder type to convert a char array to a string. We append each char to the StringBuilder, and then call ToString().

using System;
using System.Text;

// Create 3-character array.
char[] array = { 'c', 'a', 't' };
// Loop over the array with foreach, and append to a StringBuilder.
StringBuilder builder = new StringBuilder();
foreach (char value in array)
{
    builder.Append(value);
}
string result = builder.ToString();
Console.WriteLine($"STRINGBUILDER RESULT: {result}");
STRINGBUILDER RESULT: cat

Notes, string keyword

The lowercase "string" type is an alias for the String reference type. Strings reference external data—this is allocated on the managed heap.

Performance

The new string constructor is overall very efficient when compared to other approaches. It is the fastest way to make a new string in many cases.

With a constructor, we created a new string object from an array. You can run the example console program to prove the method works correctly.