Something along the lines of
string str1 = "ðə ɻɛd fɑks ɪz hʌŋgɻi";
string str2 = "ðæt ɪt foks ɪn ðʌ sʌn ɻe͡i";
char[] str1Char = str1.ToCharArray();
char[] str2Char = str2.ToCharArray();
int matchCount = 0;
int unmatchedCount = 0;
for (int x = 0; x>= str1Char.Length || x >= str2Char; x++;)
{
if (str1Char[x] == str2Char[x])
matchCount++;
else
unmatchedCount++;
}
int longestString = str1Char.Length;
if (str2Char.Length > longestString )
longestString = str2Char.Length;
int perc = (matchCount/longestString )*100;
this will fall over if the first string is shorter than the second but you get the jist