My question might looks like silly, but i struck with it.
I have a string value "155.300" and i want to convert it to integer.
I tryed but throwing System.FormatException....pls someone help me out.
Since your source data is string you need to Convert it to Double first then just cast it to int or use Convert.ToInt32, but remember Convert.ToInt32 rounds it to nearest integer number, whereas casting takes the int part of the number (truncate)
double d = Convert.ToDouble("155.00");
int a = (int) d;
int b = Convert.ToInt32(d);
Or in a single Line
int b =(int) Convert.ToDouble("155.000");
EDIT
Since you want to use decimal point as thousand separator, I believe in German culture you can try the following.
int b = ((int)Convert.ToDouble("154.500", new CultureInfo("de-DE")));
That will give you 154500
EDIT 2
Or much better is to use int.Parse with NumberStyles.AllowThousands:
int b = int.Parse("154.500", NumberStyles.AllowThousands, new CultureInfo("de-DE"));
First parse it as a decimal or double (probably best to use decimal as you've got decimal data) then either cast or use something like Math.Round, depending on your requirements.
Basically, you need to always consider what data you've got: "155.300" isn't a string representation of an integer, so don't try to parse it as an integer. Parse it as what it is, then convert that to an integer.
Alternatively, you could hack at the string representation first, but personally I find that to be a more brittle approach in many cases.
EDIT: Note that if this is really already an integer, but with a thousands separator, you don't need to use double at all - you can use int.Parse, specifying an appropriate culture and number style:
int parsed = int.Parse(text, NumberStyles.Integer | NumberStyles.AllowThousands,
culture);
Here is a working conversion sample. Take a special look with the edge conditions, the output may be different if using several rounding/casting techniques
class Program
{
public static int MyToInt(string str)
{
double result;
bool success = Double.TryParse(str, out result);
if (!success)
{
throw new ArgumentException(
"Cannot parse a string into a double");
}
return Convert.ToInt32(result); // 156
//return (int)result; // 155 <<
//return (int)Math.Round(result); // 156
}
static void Main(string[] args)
{
string s = "155.500";
int value = MyToInt(s);
}
}
You can try this:
string str = "123.123";
str = str.Remove(str.IndexOf('.'), 1);
int result;
int.TryParse(str, out result);
Edit: Based on your comment, modified to multiply by thousand.
Or you can just try:
string str = "123.123";
double result;
double.TryParse(str, out result);
int final = (int)(result * 1000);
Related
I know that C# has some options to format decimal numbers with some extended logic in the ToString() method, as e.g.
double d1 = 1.3333;
double d2 = 1.6666;
string d1Str = d1.ToString("#0.00"); // 1.33
string d2Str = d2.ToString("#0.00"); // 1.67
That's great, my number is rounded to the second decimal. But what if I wanted to round to a step of 0.05 instead of 0.01? Is there a way to use the ToString() method in a similar way to round the value not to a given step-size (e.g. 0.05)?
Note: I know I could do something like this:
(Math.Round(1.33333*20)/20).ToString();
but the question is about getting this result using ToString() only.
Is it possible for you to create an extension overload for ToString() for these components?
If so you could write something like:
public static class DoubleStaticExtension
{
public static string ToString(this double value, string format, int decimalToRoundHalfwayAt)
{
int modifier = 2 * (int)Math.Pow(10, decimalToRoundHalfwayAt -1 );
return (Math.Round(value * modifier, MidpointRounding.AwayFromZero) / modifier).ToString(format);
}
}
Calling that with
double d = 9.333333;
string result = d.ToString("#0.00", 2);
Would give a result of 9.35
And
double d = 9.333333;
string result = d.ToString("#0.00", 1);
Would give a result of 9.50
I have read the second line in a text file which contains 2.75 and I am trying to get it to do something if it meets certain criteria. I'm sure I have done this before and has a simple answer but I can't seen to figure it out.
string SecondLine;
using (var reader = new StreamReader(SPFile2))
{
reader.ReadLine();
SecondLine = reader.ReadLine();
}
int NewValue;
NewValue = Convert.ToInt32(SecondLine);
if ((NewValue >= 2) && (NewValue <= 2.99))
{
// Do Something
}
if ((NewValue >= 3) && (NewValue <= 3.99))
{
// Do something else
}
What have I missed out?
You are converting a decimal number to an Int32 that does not hold decimals. This will turn the number in NewValue into 2 as it truncates towards zero. You need to store the variable in a double, float or decimal whichever is best for your requirements.
See the following example that uses a double and Parse:
double newValue = Double.Parse(secondLine);
Note that if you are unsure if the value will be a double you should use Double.TryParse
double newValue;
bool result = Double.TryParse(secondLine, out newValue);
if (!result) //Parse failed
Note that if the parsing fails it may be down to your culture settings i.e. a ',' for the decimal separator not a '.'. However there is an overload for Parse and TryParse that allows you to pass culture information in.
You are trying to parse a string that represents a double into a integer
that will cause a
System.IFormatException
{"Input string was not in a correct
format."}{"Input string was not in a correct format."}
if you know it is a number with decimal part then do:
var newValue = Convert.ToDouble(secondLine);
if you know it is an integer then try:
var newValue = Convert.ToInt32(secondLine);
I need to save a string with the hexadecimal code of an int.
For example the hexadecimal value for the int 15 is xoooF.
My problem is that I have to save this code in a string like this:
int myint = myStringLength; //this value might change
string myIntExhCode = myint.convertThisIntoMyCode();
//and the string has to be exactly "/xoooF"
So in this question I have two problmes:
The first is how to automatically convert an int into the hexadecimal code like 15 = xoooF
The second is how to create a string containing \xoooF because any try of concatenating strings like this resulted into a \\xoooF and this is not correct since in output I need the string to be converted into the ascii code.
How can I achieve those two tasks?
Any help will be appreciated
Your question is quite vague. If you want hexadecimal format, but with 0 (digit zero) changed into o (small latin letter o) you can implement, say, an extension method (in order to keep your proposed code intact):
public static partial class IntExtensions {
public static string convertThisIntoMyCode(this int value) {
return "\\x" + value.ToString("X4").Replace('0', 'o'); // or "/x" + ...
}
}
...
int myint = myStringLength; //this value might change
string myIntExhCode = myint.convertThisIntoMyCode();
// Test output
Console.Write(myIntExhCode);
How about
int i = 15;
string result = "\\x" + i.ToString("X").PadLeft(4, 'o');
private int FindNumber(string sPar)
{
// Get the last number
int len = sPar.Length;
string s = sPar.Substring(len-1);
return new (int)Decimal(s);
}
In this I am getting the error ; required . Can any ine help me on this.
Thank You!
Change your code to this:
private int FindNumber(string sPar)
{
int len = sPar.Length;
string s = sPar.Substring(len - 1);
return Convert.ToInt32(s);
}
Or, even shorter:
private int FindNumber(string sPar)
{
return Convert.ToInt32(sPar.Substring(sPar.Length - 1));
}
I'm not 100% what you are trying to do here, but if you want to get 4 as the result from the string "17894" i guess you want to write it like this with minimum number of changes:
private int FindNumber(string sPar) {
// Get the last number
int len = sPar.Length;
string s = sPar.Substring(len-1);
return int.Parse(s);
}
No reason to include a decimal and parse it to an int if you are only taking one char of the string anyway.
Note that this will give an exception if the last char of the string for any reason is not a number.
what is Decimal(s)? If you mean "parse as a decimal, then cast to int":
return (int)decimal.Parse(s);
If it is known to be an integer, just:
return int.Parse(s);
Actually, since you are only interested in the last digit, you could cheat:
private static int FindNumber(string sPar)
{
char c = sPar[sPar.Length - 1];
if (c >= '0' && c <= '9') return (int)(c - '0');
throw new FormatException();
}
Decimal(s) is not a valid call since Decimal is a type. Try Decimal.Parse(s) instead if you are certain that s is a valid decimal, stored as a string. If not, use Decimal.TryParse instead.
Please take into account different Culture related problems also, check out the overload that takes an IFormatProvider (I think, not sure about the exact name)
Do you just want to parse the digit from the last position in the string?
private int FindNumber(string sPar)
{
return int.Parse(sPar.Substring(sPar.Length - 1));
}
Note that this will fail if (a) the string is null, (b) the string is empty, or (c) the last character of the string isn't a digit. You should add some checking to your method if these situations are likely to be a problem.
The last line is completely wrong.
Your code takes the last char of a string(that i presume is always a number) and cast it to an int.
Do the following
try{
return Int32.Parse(s);
}
catch(Exception e)
{
// manage conversion exception here
}
I suppose you want to convert string to decimal as your code is not very clear.
you can use
Decimal d1;
if(Decimal.TryParse(sPar,out d1))
{
return d1
}
else
{
return 0;
}
What is the best way to take a string which can be empty or contain "1.2" for example, and convert it to an integer? int.TryParse fails, of course, and I don't want to use float.TryParse and then convert to int.
Solution 1: Convert.ToDouble (culture-dependent)
You may using Convert.ToDouble. But, beware! The below solution will work only when the number separator in the current culture's setting is a period character.
var a = (int)Convert.ToDouble("1.2");
Solution 2: Convert.ToDouble (culture-independent)
It's preferable to use IFormatProvider and convert the number in an independent way from the current culture settings:
var a = (int)Convert.ToDouble("1.2", CultureInfo.InvariantCulture.NumberFormat);
Solution 3: Parse & Split
Another way to accomplish this task is to use Split on parsed string:
var a = int.Parse("1.2".Split('.')[0]);
Or:
var a = int.Parse("1.2".Split('.').First());
Notes
If you want to handle empty and null strings, write a method and add string.IsNullOrEmpty condition.
To get decimal separator for the current culture setting, you can use NumberFormatInfo.NumberDecimalSeparator property.
You should also keep eye on rounding to avoid traps.
Select casting, Parse, TryParse or Convert class wisely. Read more at:
How to: Convert a string to an int (C# Programming Guide)
How to: Determine Whether a String Represents a Numeric Value (C# Programming Guide)
I don't know what's wrong with parsing to a float and converting to an int. I doubt that any other way would be more efficient but here's an attempt:
//allows empty strings and floating point values
int ParseInt(string s, bool alwaysRoundDown = false)
{
//converts null/empty strings to zero
if (string.IsNullOrEmpty(s)) return 0;
if (!s.Contains(".")) return int.Parse(s);
string parts = s.Split(".");
int i = int.Parse(parts[0]);
if (alwaysRoundDown || parts.Length==1) return i;
int digitAfterPoint = int.Parse(parts[1][0]);
return (digitAfterPoint < 5) ? i : i+1;
}
In order to globalize the code you would need to replace "." with System.Globalization.CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator.
int a = (int)Math.Round(float.Parse("0.9"));
You need to round it first unless you want 0.9f being converted to 0 instead of 1.
Maybe you can try to delete everything after floating point using string functions and then convert to int. But seriously I don't think it's better than converting to float and then to int.
I think another way of doing it would be splitting the string into pieces taking the decimal (.) as the delimiter and then parsing for the integer. Of course, I am yet to ask you if the string might contain values like "37.56 miles in 32.65 seconds" type values.
Considering there will be only one value (string or number) in the string, I can think of something in the following line:
public int64 GetInt64(string input)
{
if (string.IsNullOrEmpty(input)) return 0;
// Split string on decimal (.)
// ... This will separate all the digits.
//
string[] words = input.Split('.');
return int.Parse(words[0]);
}
You can use the Visual Basic runtime Library to accomplish this from c#.
You need to add a reference to the assembly Microsoft.VisualBasic.dll to your solution.
Then the following code will do your conversion:
using VB = Microsoft.VisualBasic.CompilerServices;
class Program
{
static void Main(string[] args)
{
int i = VB.Conversions.ToInteger("1.2");
}
}
I had this same problem and ended up using a hybrid of Mark's and Dariusz':
if (num == "")
{
num = "0.00";
}
var num1 = (float)Convert.ToDouble(num);