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Non-decimal radices/Convert: Difference between revisions
C#
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Line 427:
return result;
}</lang>
=={{header|C#}}==
<lang CSharp>
public static class BaseConverter {
/// <summary>
/// Converts a string to a number
/// </summary>
/// <returns>The number.</returns>
/// <param name="s">The string to convert.</param>
/// <param name="b">The base number (between 2 and 36).</param>
public static long stringToLong(string s, int b) {
if ( b < 2 || b > 36 )
throw new ArgumentException("Base must be between 2 and 36", "b");
checked {
int slen = s.Length;
long result = 0;
bool isNegative = false;
for ( int i = 0; i < slen; i++ ) {
char c = s[i];
int num;
if ( c == '-' ) {
// Negative sign
if ( i != 0 )
throw new ArgumentException("A negative sign is allowed only as the first character of the string.", "s");
isNegative = true;
continue;
}
if ( c > 0x2F && c < 0x3A )
// Numeric character (subtract from 0x30 ('0') to get numerical value)
num = c - 0x30;
else if ( c > 0x40 && c < 0x5B )
// Uppercase letter
// Subtract from 0x41 ('A'), then add 10
num = c - 0x37; // 0x37 = 0x41 - 10
else if ( c > 0x60 && c < 0x7B )
// Lowercase letter
// Subtract from 0x61 ('a'), then add 10
num = c - 0x57; // 0x57 = 0x61 - 10
else
throw new ArgumentException("The string contains an invalid character '" + c + "'", "s");
// Check that the digit is allowed by the base.
if ( num >= b )
throw new ArgumentException("The string contains a character '" + c + "' which is not allowed in base " + b, "s");
// Multiply the result by the base, then add the next digit
result *= b;
result += num;
}
if ( isNegative )
result = -result;
return result;
}
}
/// <summary>
/// Converts a number to a string.
/// </summary>
/// <returns>The string.</returns>
/// <param name="n">The number to convert.</param>
/// <param name="b">The base number (between 2 and 36).</param>
public static string longToString(long n, int b) {
// This uses StringBuilder, so it only works with .NET 4.0 or higher. For earlier versions, the StringBuilder
// can be replaced with simple string concatenation.
if ( b < 2 || b > 36 )
throw new ArgumentException("Base must be between 2 and 36", "b");
// If the base is 10, call ToString() directly, which returns a base-10 string.
if ( b == 10 )
return n.ToString();
checked {
long longBase = b;
StringBuilder sb = new StringBuilder();
if ( n < 0 ) {
// Negative numbers
n = -n;
sb.Append('-');
}
long div = 1;
while ( n / div >= b )
// Continue multiplying the dividend by the base until it reaches the greatest power of
// the base which is less than or equal to the number.
div *= b;
while ( true ) {
byte digit = (byte) (n / div);
if ( digit < 10 )
// Numeric character (0x30 = '0')
sb.Append((char) (digit + 0x30));
else
// Alphabetic character (for digits > 10) (0x61 = 'a')
sb.Append((char) (digit + 0x57)); // 0x61 - 10
if ( div == 1 )
// Stop when the dividend reaches 1
break;
n %= div;
div /= b;
}
return sb.ToString();
}
}
}
</lang>
=={{header|Caché ObjectScript}}==
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