String to int
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musefan has given you the perfect answer. Just be aware that if the number can't be converted to an int you will get zero. I have an extension method that I use when working with text/xml etc files to simplify stuff.
public static class ExtensionMethods
{
/// <summary>
/// Converts a string to an integer.
/// </summary>
/// <param name="value">The string to convert.</param>
/// <returns>The integer value of the string if valid; otherwise, zero.</returns>
public static Int32 ToInt32(this string value)
{
int result;
Int32.TryParse(value, out result);
return result;
}
}Now I can can just use something like
int intFromFile = stringFromFile.ToInt32();
Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)If I might... Is it considered really bad practice to do Convert.ToInt32 ? I have seen stuff (and well, I have used it, too) like:
string x = "10";
int xInt;
try
{
xInt = Convert.ToInt32(x);
}
catch
{
xInt = 0;
}Would that not do the same as TryParse? Or is it an unnecessary way around it, or simply, crap?
var question = (_2b || !(_2b));
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what's the difference between the method you've used and result = int.parse("100000");
there is no difference
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what's the difference between the method you've used and result = int.parse("100000");
The difference is that if you pass a string to int.parse() that is not a valid string (contains noon-numeric characters) it will throw an exception that you will need to manually handle. If you use my method the error is handled automatically and the result is set to 0, its up to you if you want to handle the error yourself thou, depends how much validation control you need. if you are expecting the result could sometimes be 0 as a result then you may be best to handle the error yourself. but in the case of a port number you shouldnt need to do this, just check if result is 0 for an error.
Life goes very fast. Tomorrow, today is already yesterday.
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what's the difference between the method you've used and result = int.parse("100000");
If the input string is not a valid integer,
int.Parsethrows an exception, whileint.TryParsereturns false without setting result value. e.g.string wrong = "xyz";
result = int.Parse(wrong); // an exception is thrown herestring wrong = "xyz";
int result = -1;
bool success = int.TryParse(wrong, out result); // success is false, while result will still be -1 -
The difference is that if you pass a string to int.parse() that is not a valid string (contains noon-numeric characters) it will throw an exception that you will need to manually handle. If you use my method the error is handled automatically and the result is set to 0, its up to you if you want to handle the error yourself thou, depends how much validation control you need. if you are expecting the result could sometimes be 0 as a result then you may be best to handle the error yourself. but in the case of a port number you shouldnt need to do this, just check if result is 0 for an error.
Life goes very fast. Tomorrow, today is already yesterday.
Thank you for the reply... next time I convert I'll bare it in mind.
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If the input string is not a valid integer,
int.Parsethrows an exception, whileint.TryParsereturns false without setting result value. e.g.string wrong = "xyz";
result = int.Parse(wrong); // an exception is thrown herestring wrong = "xyz";
int result = -1;
bool success = int.TryParse(wrong, out result); // success is false, while result will still be -1Thanks for the reply, however according to the above post the result would be set to zero and not stay at -1 or is it only set to zero if there is no valid number in it?
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Thanks for the reply, however according to the above post the result would be set to zero and not stay at -1 or is it only set to zero if there is no valid number in it?
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The difference is that if you pass a string to int.parse() that is not a valid string (contains noon-numeric characters) it will throw an exception that you will need to manually handle. If you use my method the error is handled automatically and the result is set to 0, its up to you if you want to handle the error yourself thou, depends how much validation control you need. if you are expecting the result could sometimes be 0 as a result then you may be best to handle the error yourself. but in the case of a port number you shouldnt need to do this, just check if result is 0 for an error.
Life goes very fast. Tomorrow, today is already yesterday.
musefan wrote:
just check if result is 0 for an error
Better to assign and check the boolean return value of the TryParse method before working with the value. Still preferable to catching an exception!
Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia) -
Yes, I was wrong,
int.TryParseputs 0 in the result if the parsing fails. For some reason, I tought that the resul value was unchanged in case of failure, my bad.No worries thanks for the clarification
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Thanks for the reply, however according to the above post the result would be set to zero and not stay at -1 or is it only set to zero if there is no valid number in it?
hopingToCode wrote:
only set to zero if there is no valid number
... or if the number in the text is zero! Check the return value of the TryParse method to determine if successful.
Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia) -
musefan wrote:
just check if result is 0 for an error
Better to assign and check the boolean return value of the TryParse method before working with the value. Still preferable to catching an exception!
Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia) -
If I might... Is it considered really bad practice to do Convert.ToInt32 ? I have seen stuff (and well, I have used it, too) like:
string x = "10";
int xInt;
try
{
xInt = Convert.ToInt32(x);
}
catch
{
xInt = 0;
}Would that not do the same as TryParse? Or is it an unnecessary way around it, or simply, crap?
var question = (_2b || !(_2b));
Not bad practice, possibly a little slower going via the Convert class but I would have to check the implementation to be sure. The convert class is great for converting from a built in type to another (not just from string), but I would guess the Int32.Parse or Int32.TryParse methods would be perhaps a little more efficient.
Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)