I have this array
char[] A = ['1', '2', '3', '4']
And I want to convert it to int[]
int[] Aint=[1, 2, 3, 4]
Any ideas?
I just started programming
Thanks
6 Answers
Another option, using Array.ConvertAll and Char.GetNumericValue:
int[] Aint = Array.ConvertAll(A, c => (int)Char.GetNumericValue(c));
11 Comments
Gray
I think this is the best solution so far because it is extremely easier to read and understand at a glance. It's practically written in plain English.
Douglas
Is there any reason why you used
Array.ConvertAll instead of Select(…).ToArray()? I'm asking because the latter seems to be much more in vogue nowadays (and your lambda expression requires C# 3 anyway).
Tim Schmelter
@Douglas:
Array.ConvertAll is just more efficient than Select..ToArray since it pre-allocates a correctly-sized array and doesn't do any resizing. It's also readable/explicit as Gray has already mentioned.Tim Schmelter
@Douglas: Also, it works already with .NET 2 even with the lambda.
Douglas
@TimSchmelter: Yes, I agree it's more efficient in that respect. By mentioning C# 3, I meant that it requires the same version of C# (and .NET) as LINQ would.
|
To get the numeric value of a digit character ('0' to '9'), you can simply subtract the codepoint of '0' from its own.
int[] Aint = A.Select(a => a - '0').ToArray();
The digit characters are assigned consecutive codepoints. '0' has codepoint 48; '1' has codepoint 49; and so on until '9', which has codepoint 57. Thus, when you subtract two digit characters, you would get the same result as if you were subtracting their numeric values. Subtracting '0' from any digit would give you the latter's absolute value.
2 Comments
Marco Lackovic
You need to have the System.Linq namespace included in your code because of the use of the Select method. You can do this by adding
using System.Linq to the top of your code.Douglas
@Krige: You're right. Visual Studio 2013 includes it automatically for you when you create a new class file.
Add a using statement for using System.Linq; then you can do the following:
int[] Aint = A.Select(i => Int32.Parse(i.ToString())).ToArray();
You will get an exception if an element in A cannot be parsed.
2 Comments
Henk Holterman
Concise is usually good but not so much for someone who has "just started programming".
Adam Modlin
Well he didn't ask for a specific implementation (for loop, while loop, etc) and I like Linq so that's how I implemented it.
Please do Like this
char[] A = {'1', '2', '3', '4'};
int[] Aint = new int[A.Length];
for (int i = 0;i < A.Length;i++)
{
Aint[i] = Convert.ToInt32(A[i].ToString());
}
1 Comment
Jordan
Convert.ToInt32, small mistake in solution.
A little bit of Linq should do the trick:
int[] Aint = A.Select(c => c - 48).ToArray(); // or c - '0'
Comments
You can also do this:
int[] Aint = A.Select(c => Convert.ToInt32(c.ToString())).ToArray();
This will select all character array as string, converts them to array, then return an integer of array.
charto it's correspondingintvalue? Do you know how to create a new array based on another array's values?