This question already has answers here:
How can I convert String to Int?
(31 answers)
Closed 3 years ago.
I can't get the string of text_box.text to convert to an int then compare to another int.
I also need to check to see if the string of text_box.text can be turned into an int.
I've tried .ToInt32, which I have always used and it has been fine. I have no idea how to test if the string of text_box can be turned into an int.
public static void before (int bS)
{
beforeScore = bS;
}
//some space later
if (score_bet_text_box.Text.ToInt32() > beforeScore)
{
MessageBox.Show("You can't bet more than you have", "game");
}
I expect it to convert the string of text_box into an int, then compare it to the other int.
I also hope to test if it can be converted into an int, but have no clue how so it is not shown in the code above.
ToInt32 isn't a method on a string unless you have an extension method somewhere. You want to use the TryParse method as follows...
if(int.TryParse(score_bet_text_box.Text, out int result))
{
if(result > beforeScore)
{
MessageBox.Show("You can't bet more than you have", "game");
}
}
If you are using an older version of C# you'll have to define result outside the if as follows:
int result;
if(int.TryParse(score_bet_text_box.Text, out result))
Related
This question already has answers here:
Input string was not in a correct format
(9 answers)
Closed 3 years ago.
C# CODE
I have a problem with my "Check in" form.
I want to multiply the txtsubtotal and txtadvancepayment.
In textchange if I put number on the txtadvancepayment, the overallresult is correct. But if I clear the txtadvancepayment (Incase when the user puts a wrong value) it would be error. The error says "Input string was not in a correct format."
What should I do?
My Code downward
int overalltotal = 0;
int a = Convert.ToInt32(txtsubtotal.Text);
int b = Convert.ToInt32(txtadvancepayment.Text);
overalltotal = a - b;
txttotalbalance.Text = overalltotal.ToString();
An empty string cannot be parsed as an int. As others have mentioned, you can use int.TryParse which accepts a string as the first parameter and an out int as the second parameter, which holds the parsed value. You could do this:
int overallTotal = 0;
int a = 0;
int b = 0;
// TryParse returns a bool
// If either of these fails, the variable a or b will keep the default 0 value
int.TryParse(txtSubtotal.Text, out a);
int.TryParse(txtAdvancePayment.Text, out b);
// Sum a and b
overallTotal = a + b;
If you want to show an error to the user that one or both fields isn't a valid integer, you can assign a bool variable such as var aIsNumber = int.TryParse(...) and then check if aIsNumber or bIsNumber is false. If so, then a and/or b could not be parsed to an int.
You could use Int32.TryParse.
Int32.Parse attempts to convert the string representation of a number to its 32-bit signed integer equivalent and returns value indicates whether the operation succeeded. This would mean, in case your textbox is empty or contains a invalid numeric representation, and the method would return false since it would not be able to convert it to int32
For example
if(Int32.TryParse(txtsubtotal.Text,out var a)
&& Int32.TryParse(txtadvancepayment.Text,out var b))
{
// Code which requires a and b
}
This question already has answers here:
Int32.TryParse() returns zero on failure - success or failure?
(6 answers)
Closed 5 years ago.
I'm baffled on the tiny piece of code below that fails to return 957 as I would expect. I'm kind of embarrassed to post but I can't see the problem.
using System;
namespace ConsoleApp1
{
internal class Program
{
private static void Main(string[] args)
{
Console.WriteLine(ConvertToInteger("957.13"));
}
private static string ConvertToInteger(string timeStartIn)
{
Int32.TryParse(timeStartIn, out var timeStart);
return timeStart.ToString();
}
}
}
You should check Int32.TryParse method help.
It says:
When this method returns, contains the 32-bit signed integer value equivalent of the number contained in s, if the conversion succeeded, or zero if the conversion failed.
Since 957.13 is a string representing a decimal value, TryParse method returns 0 because a decimal number is not an integer one.
You are dealing with a float or a decimal type, use a floor or ceiling function then you can convert it to a full number integer. You could also convert it to a string and split it by the decimal point, then use only the first segment and convert that to a full number integer.
NOTE: The string method does not take rounding into account.
This question already has answers here:
Validate Enum Values
(12 answers)
Closed 6 years ago.
If I create an enum like this
public enum ImportType
{
Direct,
Indirect,
InBond
}
and I have a method that takes an ImportType as parameter as follows
public bool ProcessValidImport(ImportType type)
{
// Process ImportType variable here
}
I can go and call the method as follows
bool blnProcessed = ProcessValidImport((ImportType)7);
But the ImportType variable value of 7 passed in to the method is not valid at all because any integer will work if cast. The enum defaults to an int type, so what is the best way to validate that an enum in this case is in fact a valid ImportType.
I don't know if I understood you correctly but you can validate enum easily using:
int value = 7;
bool isDefined = Enum.IsDefined(typeof (ImportType), value);
This question already has answers here:
How can I check if a string is a number?
(25 answers)
Closed 8 years ago.
I have a string list array that contains strings. Either the values will be a name or number. For example the contents could be:
stringList[0]="Mary"
stringList[1]="John"
stringList[2]="4564321"
stringList[3]="Steven"
I want to append the contents of the list to a string which I have done through a simple loop but if a number is encountered I want that number to be popped out and handled in a different method and then have the original loop continue looking for strings and appending. Essentially I want to append the non numbers and take the numbers and do something else with them. What functions or tricks can I do so when it is going through the list it will be able to identify a string as a number?
As long as the string is always a number (not numbers and letters mixed), you an use one of the various TryParse methods. I'll use int in my example, but you can use whichever fits your needs:
int value;
foreach(var s in stringList)
{
if(int.TryParse(s, out value))
{
// s was a number, the parsed result is in value
}
else
{
// s was something else
}
}
You can use int.TryParse to determine if it's a number and get its value.
int intValue;
if (int.TryParse(str, out intValue))
// handle as int
else
// handle as string
This question already has answers here:
How to convert string to integer in C#
(12 answers)
Closed 8 years ago.
I need to convert a string to integer. My string can be of any type (float/int/string/special character).
For example:
If my string is "2.3", I need to convert to = 2
If my string is "anyCharacter", I need to convert to = 0
If my string is "2", I need to convert to = 2
I tried the following:
string a = "1.25";int b = Convert.ToInt32(a);
I got the error:
Input string was not in a correct format
How do I convert it?
Use Double.TryParse() and once you get the value from it, convert it to int using Convert.ToInt():
double parsedNum;
if (Double.TryParse(YourString, out parsedNum) {
newInt = Convert.ToInt32(num);
}
else {
newInt = 0;
}
Try to parse it as a floating point number, and convert to integer after that:
double num;
if (Double.TryParse(a, out num) {
b = (int)num;
} else {
b = 0;
}
This should help: treat any string as if it were a double, then Math.Floor() it to round it down to the nearest integer.
double theNum = 0;
string theString = "whatever"; // "2.3"; // "2";
if(double.TryParse(theString, out theNum) == false) theNum = 0;
//finally, cut the decimal part
int finalNum = (int)Math.Floor(theNum);
NOTE: the if might not be needed per-se, due to theNum initialization, but it's more readable this way.
I think Convert.ToInt32 is the wrong place to look for - I would use Integer.Tryparse and if TryParse evaluates to false, assign a 0 to the variable. Before the TryParse, you could simply delete any character after the dot, if you find it in the string.
Also, keep in mind that some languages use "," as a separator.
Try:
if (int.TryParse(string, out int)) {
variable = int.Parse(string);
}
As far as I know, there isn't any generic conversion, so you'd have to do a switch to find out the type of the variable and then use either of the following (for each type):
int.Parse(string)
or
int.TryParse(string, out int)
The second one will return a boolean which you can use to see if the conversion passed or failed.
Your best option would be to use double or decimal parsing as this won't remove any decimal places, unlike int.
bool Int32.TryParse(string, out int)
The boolean return value indicates if the conversion was successful or not.
Try something like this:
public int ForceToInt(string input)
{
int value; //Default is zero
int.TryParse(str, out value);
return value;
}
This will do the trick. However I don't recommend taking this approach. It is better to control your input whereever you get it.