I have a char in c#:
char foo = '2';
Now I want to get the 2 into an int. I find that Convert.ToInt32 returns the actual decimal value of the char and not the number 2. The following will work:
int bar = Convert.ToInt32(new string(foo, 1));
int.parse only works on strings as well.
Is there no native function in C# to go from a char to int without making it a string? I know this is trivial but it just seems odd that there's nothing native to directly make the conversion.
This will convert it to an int:
char foo = '2';
int bar = foo - '0';
This works because each character is internally represented by a number. The characters '0' to '9' are represented by consecutive numbers, so finding the difference between the characters '0' and '2' results in the number 2.
Has anyone considered using int.Parse() and int.TryParse() like this
int bar = int.Parse(foo.ToString());
Even better like this
int bar;
if (!int.TryParse(foo.ToString(), out bar))
{
//Do something to correct the problem
}
It's a lot safer and less error prone
I'm using Compact Framework 3.5, and not has a "char.Parse" method. I think is not bad to use the Convert class. (See CLR via C#, Jeffrey Richter)
char letterA = Convert.ToChar(65);
Console.WriteLine(letterA);
letterA = '?';
ushort valueA = Convert.ToUInt16(letterA);
Console.WriteLine(valueA);
char japaneseA = Convert.ToChar(valueA);
Console.WriteLine(japaneseA);
Works with ASCII char or Unicode char
This will convert it to an int:
char foo = '2';
int bar = foo - '0';
This works because each character is internally represented by a number. The characters '0' to '9' are represented by consecutive numbers, so finding the difference between the characters '0' and '2' results in the number 2.
I am agree with @Chad Grant
Also right if you convert to string then you can use that value as numeric as said in the question
int bar = Convert.ToInt32(new string(foo, 1)); // => gives bar=2
I tried to create a more simple and understandable example
char v = '1';
int vv = (int)char.GetNumericValue(v);
char.GetNumericValue(v) returns as double and converts to (int)
More Advenced usage as an array
int[] values = "41234".ToArray().Select(c=> (int)char.GetNumericValue(c)).ToArray();
By default you use UNICODE so I suggest using faulty's method
int bar = int.Parse(foo.ToString());
Even though the numeric values under are the same for digits and basic Latin chars.
Has anyone considered using int.Parse() and int.TryParse() like this
int bar = int.Parse(foo.ToString());
Even better like this
int bar;
if (!int.TryParse(foo.ToString(), out bar))
{
//Do something to correct the problem
}
It's a lot safer and less error prone
I've seen many answers but they seem confusing to me. Can't we just simply use Type Casting.
For ex:-
int s;
char i= '2';
s = (int) i;
This will convert it to an int:
char foo = '2';
int bar = foo - '0';
This works because each character is internally represented by a number. The characters '0' to '9' are represented by consecutive numbers, so finding the difference between the characters '0' and '2' results in the number 2.
Principle:
char foo = '2';
int bar = foo & 15;
The binary of the ASCII charecters 0-9 is:
0 - 0011 0000
1 - 0011 0001
2 - 0011 0010
3 - 0011 0011
4 - 0011 0100
5 - 0011 0101
6 - 0011 0110
7 - 0011 0111
8 - 0011 1000
9 - 0011 1001
and if you take in each one of them the first 4 LSB (using bitwise AND with 8'b00001111 that equals to 15) you get the actual number (0000 = 0,0001=1,0010=2,... )
Usage:
public static int CharToInt(char c)
{
return 0b0000_1111 & (byte) c;
}
char c = '1';
int i = (int)(c-'0');
and you can create a static method out of it:
static int ToInt(this char c)
{
return (int)(c - '0');
}
By default you use UNICODE so I suggest using faulty's method
int bar = int.Parse(foo.ToString());
Even though the numeric values under are the same for digits and basic Latin chars.
This worked for me:
int bar = int.Parse("" + foo);
I am agree with @Chad Grant
Also right if you convert to string then you can use that value as numeric as said in the question
int bar = Convert.ToInt32(new string(foo, 1)); // => gives bar=2
I tried to create a more simple and understandable example
char v = '1';
int vv = (int)char.GetNumericValue(v);
char.GetNumericValue(v) returns as double and converts to (int)
More Advenced usage as an array
int[] values = "41234".ToArray().Select(c=> (int)char.GetNumericValue(c)).ToArray();
char c = '1';
int i = (int)(c-'0');
and you can create a static method out of it:
static int ToInt(this char c)
{
return (int)(c - '0');
}
Try This
char x = '9'; // '9' = ASCII 57
int b = x - '0'; //That is '9' - '0' = 57 - 48 = 9
Principle:
char foo = '2';
int bar = foo & 15;
The binary of the ASCII charecters 0-9 is:
0 - 0011 0000
1 - 0011 0001
2 - 0011 0010
3 - 0011 0011
4 - 0011 0100
5 - 0011 0101
6 - 0011 0110
7 - 0011 0111
8 - 0011 1000
9 - 0011 1001
and if you take in each one of them the first 4 LSB (using bitwise AND with 8'b00001111 that equals to 15) you get the actual number (0000 = 0,0001=1,0010=2,... )
Usage:
public static int CharToInt(char c)
{
return 0b0000_1111 & (byte) c;
}
I'm using Compact Framework 3.5, and not has a "char.Parse" method. I think is not bad to use the Convert class. (See CLR via C#, Jeffrey Richter)
char letterA = Convert.ToChar(65);
Console.WriteLine(letterA);
letterA = '?';
ushort valueA = Convert.ToUInt16(letterA);
Console.WriteLine(valueA);
char japaneseA = Convert.ToChar(valueA);
Console.WriteLine(japaneseA);
Works with ASCII char or Unicode char
char c = '1';
int i = (int)(c-'0');
and you can create a static method out of it:
static int ToInt(this char c)
{
return (int)(c - '0');
}
Comparison of some of the methods based on the result when the character is not an ASCII digit:
char c1 = (char)('0' - 1), c2 = (char)('9' + 1);
Debug.Print($"{c1 & 15}, {c2 & 15}"); // 15, 10
Debug.Print($"{c1 ^ '0'}, {c2 ^ '0'}"); // 31, 10
Debug.Print($"{c1 - '0'}, {c2 - '0'}"); // -1, 10
Debug.Print($"{(uint)c1 - '0'}, {(uint)c2 - '0'}"); // 4294967295, 10
Debug.Print($"{char.GetNumericValue(c1)}, {char.GetNumericValue(c2)}"); // -1, -1
char c = '1';
int i = (int)(c-'0');
and you can create a static method out of it:
static int ToInt(this char c)
{
return (int)(c - '0');
}
Comparison of some of the methods based on the result when the character is not an ASCII digit:
char c1 = (char)('0' - 1), c2 = (char)('9' + 1);
Debug.Print($"{c1 & 15}, {c2 & 15}"); // 15, 10
Debug.Print($"{c1 ^ '0'}, {c2 ^ '0'}"); // 31, 10
Debug.Print($"{c1 - '0'}, {c2 - '0'}"); // -1, 10
Debug.Print($"{(uint)c1 - '0'}, {(uint)c2 - '0'}"); // 4294967295, 10
Debug.Print($"{char.GetNumericValue(c1)}, {char.GetNumericValue(c2)}"); // -1, -1
This converts to an integer and handles unicode
CharUnicodeInfo.GetDecimalDigitValue('2')
You can read more here.
This worked for me:
int bar = int.Parse("" + foo);
The real way is:
int theNameOfYourInt = (int).Char.GetNumericValue(theNameOfYourChar);
"theNameOfYourInt" - the int you want your char to be transformed to.
"theNameOfYourChar" - The Char you want to be used so it will be transformed into an int.
Leave everything else be.
Has anyone considered using int.Parse() and int.TryParse() like this
int bar = int.Parse(foo.ToString());
Even better like this
int bar;
if (!int.TryParse(foo.ToString(), out bar))
{
//Do something to correct the problem
}
It's a lot safer and less error prone
Try This
char x = '9'; // '9' = ASCII 57
int b = x - '0'; //That is '9' - '0' = 57 - 48 = 9
I've seen many answers but they seem confusing to me. Can't we just simply use Type Casting.
For ex:-
int s;
char i= '2';
s = (int) i;
The real way is:
int theNameOfYourInt = (int).Char.GetNumericValue(theNameOfYourChar);
"theNameOfYourInt" - the int you want your char to be transformed to.
"theNameOfYourChar" - The Char you want to be used so it will be transformed into an int.
Leave everything else be.
This will convert it to an int:
char foo = '2';
int bar = foo - '0';
This works because each character is internally represented by a number. The characters '0' to '9' are represented by consecutive numbers, so finding the difference between the characters '0' and '2' results in the number 2.
Source: Stackoverflow.com