How to convert a string's chars into an array of ints

Question

I am trying to take the user's input and convert it into an array of ints. The problem is that when I choose 4 numbers, e.g. 2463 the output for the string is correct, but the output for the int array is incorrect and seems to be the number chosen + 48.

I'm not really sure why this is occurring. Thanks for any help given.

string userChoiceAsString;
int[] userChoice = new int[4];

userChoiceAsString = (Console.ReadLine());

for (int i = 0; i < userChoiceAsString.Length; i++)
{
    userChoice[i] = userChoiceAsString[i];
    Console.WriteLine(userChoice[i]);
    Console.WriteLine(userChoiceAsString[i]);
}

Hint: Take a look at what happens when the input is "X Y Z". — Tom Blodget
– Tom Blodget, Commented Jan 1, 2015 at 21:26

Christos · Accepted Answer · 2015-01-01 14:05:16Z

2

This is reasonable, because when a user inputs the character 2, this corresponds to the decimal 50. This is associated with the ASCII table.

Please have a look here.

In order to avoid this, you should try to parse the each character, like below:

userChoice[i] = Int32.Parse(userChoiceAsString[i].ToString());

or you could make use of Char's method GetNumericValue which returns a float number and then cast this to an int.

userChoice[i] = (int)Char.GetNumericValue(userChoiceAsString[i]);

edited Jan 1, 2015 at 14:05

answered Jan 1, 2015 at 14:00

Christos

54.1k9 gold badges82 silver badges114 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Tom Blodget Over a year ago

.NET strings are counted sequences of UTF-16 code-units, one or two of which encode a Unicode codepoint. So, instead of looking at an ASCII table, you should look at a Unicode table. Here's a pretty partial one. Here's the full Unicode table.

Pankov · Accepted Answer · 2015-01-01 14:01:55Z

2

You need to convert the ASCII value to int using int.Parse(), otherwise you're printing the ASCII value.

answered Jan 1, 2015 at 14:01

Pankov

1011 gold badge3 silver badges6 bronze badges

Comments

Codeek · Accepted Answer · 2015-01-01 14:00:57Z

0

try :

userChoice[i] = (int)Char.GetNumericValue(userChoiceAsString[i]);

answered Jan 1, 2015 at 14:00

Codeek

1,6341 gold badge11 silver badges20 bronze badges

Comments

fejesjoco · Accepted Answer · 2015-01-01 14:03:47Z

The number 0 that we all know is represented by the character that has a numerical value of 48 in ASCII, Unicode and several other character sets. The letter A is 65, etc. This has literally nothing to do with the actual numerical value, since characters also represent letters and millions of other glyphs which have no numerical value.

You can look at the Char.GetNumericValue method, but note that it also returns the numerical value of pi, e, and other numerals from all kinds of character sets.

What we usually do is check if the character is between '0' and '9', and if so, get the value as (int)ch - (int)'0'. This returns how far away your number is from the '0' character, thus the 0..9 value you are looking for. It just so happens that the characters '0'..'9' are after each other (it just makes sense, but it's not necessarily so).

You can also try int.Parse on a single character or the whole string. That also handles the usual decimal digits as you would expect.

Collectives™ on Stack Overflow

How to convert a string's chars into an array of ints

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related