Hello I am trying to convert String to Integer.
The code below shows a part from where I am trying to convert my string to integer.
if (other.gameObject.CompareTag("PickUp"))
{
if ( checkpointboolean == false)
{
string pickupName = other.ToString(); //other = Pickup4
//Remove first 6 letters thus remaining with '4'
string y = pickupName.Substring(6);
print(y); // 4 is being printed
int x = 0;
int.TryParse(y, out x);
print (x); // 0 is being printed
I also tried the below code and instead of '0' I am getting the following error:
if (other.gameObject.CompareTag("PickUp"))
{
if ( checkpointboolean == false)
{
//Get Object name ex: Pickup4
string pickupName = other.ToString();
//Remove first 6 letters thus remaining with '4'
string y = pickupName.Substring(6);
print(y);
int x = int.Parse(y);
FormatException: Input string was not in the correct format
System.Int32.Parse (System.String s)
int.TryParse returns a boolean, true if it succeeded and false if not. You need to wrap this in a if block and do something with that logic.
if(int.TryParse(y, out x))
print (x); // y was able to be converted to an int
else
// inform the caller that y was not numeric, your conversion to number failed
As far as why your number is not converted I could not say until you post what the string value is.
Your first attempt is the best for this case, that code works fine, The int.TryParse() giving 0 to the out parameter and returns false means the conversion is failed. The input string is not in the correct format/ it cannot be converted to an integer. You can check this by using the return value of the int.TryParse(). For this what you need to do is :-
if(int.TryParse(y, out x))
print (x); //
else
print ("Invalid input - Conversion failed");
First of all, ToString() usually uses for debug purpose so there's no guarantee that
other.ToString()
will return the expected "Pickup4" in the next version of the software. You, probably, want something like
int x = other.gameObject.SomeProperty;
int x = other.SomeOtherProperty;
int x = other.ComputePickUp();
...
If you, however, insist on .ToString() you'd rather not hardcode six letters (the reason is the same: debug information tends to change from version to version), but use regular expressions or something:
var match = Regex.Match(other.ToString(), "-?[0-9]+");
if (match.Success) {
int value;
if (int.TryParse(match.Value, out value))
print(value);
else
print(match.Value + " is not an integer value");
}
else
print("Unexpected value: " + other.ToString());
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
}
I have an int and a double, but as soon as I try to subtract the integer from the double, the following error is thrown:
Input string was not in a correct format.
Now lets look at the code:
double TotalNoRegis = values.Sum(); // This is a LIST and its = 1569
string otherFe ="600";
double totalafter;
if(otherFe != string.Empty || otherFe!= "") // This part works fine
{
totalafter = TotalNoRegis - Convert.ToInt32(otherFe); // Here the error is thrown
}
What am I doing wrong here? I looked at this Example, which is basically the same thing: int x = 1 and int y = 2 and then int this = x-y;
Please let me know if you know the issue here.
What am I doing wrong here?
Lots.
if(otherFe != string.Empty || otherFe!= "") // This part works fine
That's nonsensical code. string.Empty and "" are the same string.
Instead use
if (!string.IsNullOrEmpty(otherFe))
Moving on:
totalafter = TotalNoRegis - Convert.ToInt32(otherFe); // Here the error is thrown
You claim that the error is the subtraction, but it is not. The problem is in the ToInt32. You are passing some other string than the one you are showing.
The way I like to do this is by making an extension method:
static public class Extensions
{
public static int? ParseAsInteger(this string s) {
if (string.IsNullOrEmpty(s)) return null;
int i;
return int.TryParse(s, out i) ? (int?)i : (int?)null;
}
// Similarly write `ParseAsDouble` and so on.
}
Now you have an extension you can use:
double? totalAfter = TotalNoRegis - otherFe.ParseAsInteger();
(Or ParseAsDouble, or whatever.)
If otherFe was valid, then totalAfter has the total; if it was not, then it is null.
The lesson here is: move the type conversion logic into its own method which you can independently test. Then the logic at the call site of that method becomes simpler and easier to follow.
You should use an integer instead of a double, especially if you don't have a reason to use the double. So to rectify, you could simply do the following.
int total = values.Sum();
var other = "6000";
if(!string.IsNullOrEmpty(other))
if(int.TryParse(other, out int subtractor))
total -= subtractor;
If you require a double, then use but if you don't why bother? Also, you are subtracting fifteen hundred items from six thousand, your total after will always be negative or often be negative. Is that your desired intent?
Something to note, with the TryParse if it fails it'll skip the subtraction rather than fail like parse or convert would do. Also do you want the sum of the list or count?
I am currently working on a program and I am finalising it by going over with error handling. I have several cases which look like:
int stockbankInput = Convert.ToInt32(Console.ReadLine());
Here, the user must enter either 1, 2, 3. I have tried to use an if statement to catch the error if anybody inputs a blankspace/string/character or a number that is not 1,2 or 3 but it doesn't work in the same sense as a string input. Below is what I have tried:
if(stockbankInput == null)
{
Console.WriteLine("Error: Please enter either 1, 2 or 3");
stockbankInput = 0;
goto menuRestartLine;
}
However, you cannot link 'null' with an integer input, only a string. Can anybody help with this please?
Use the Int32 TryParse method:
int input;
var successful = Int32.TryParse(Console.ReadLine(), out input);
if (!successful)
// do something else
else
return input;
You're checking if an int is null, which will always return false because an int cannot be null.
You can use 'int?' (Nullable int) but Convert.ToInt32 will not return null. If the value of the int cannot be resolved it will resolve to the default value of zero. You can either check if the returned int is zero or do some further checking of the returned string:
int input = 0;
string errorMessage = "Error: Please enter either 1, 2 or 3";
while(true)
{
try
{
input = Convert.ToInt32(Console.ReadLine());
if (input == 0 || input > 3)
{
Console.WriteLine(errorMessage);
}
else
{
break;
}
}
catch(FormatException)
{
Console.WriteLine(errorMessage);
}
}
With this you your returned value "int input" will either be 0 or the number you entered and FormatExceptions caused by the string to convert containing symbols other than the digits 0-9 will be caught in the try/catch statement.
give this sample program a try:
static void Main(string[] args)
{
int stockbankInput = 0;
bool firstTry = true;
while(stockbankInput < 1 | stockbankInput > 3)
{
if(!firstTry)
Console.WriteLine("Error: Please enter either 1, 2 or 3");
firstTry = false;
Int32.TryParse(Console.ReadLine(), out stockbankInput);
}
}
First of all, don't use goto statements. They are considered bad practice, and it's like a blinding red light when reading your question - that's all I can focus on.
As per your question, an int or Int32 cannot be null. So you can't compare it to null. Give it a default value, and then check that.
This is a scenario where you don't need to check for an error, but just need to validate input. Use TryParse, which will set your out parameter if the parse is successful, or else set it to 0.
Next, you want to loop until you are given good input. An if statement is executed once, a loop will guarantee that when you leave it, your input will be valid.
Lastly, the firstTry is just a nice way to let the user know, after their first try, that they screwed up.
Consider this code:
var x = "tesx".Remove('x');
If I run this code, I get this exception:
startIndex must be less than length of string.
Why can I pass a char instead of an int to this method?
Why don't I get a compilation error?
Why does the compiler have this behavior?
you try to remove 'x' which is a declared as char, x is equal to 120
The .Remove only takes 2 parameters of type int the start and (optional) count to remove from the string.
If you pass a char, it will be converted to the integer representation. Meaning if you pass 'x' -> 120 is greater than the string's .Length and that's why it will throw this error!
Implicit conversion lets you compile this code since char can be converted to int and no explicit conversion is required. This will also compile and the answer will be 600 (120*5) -
char c = 'x';
int i = c;
int j = 5;
int answer = i * j;
From MSDN, implicit conversion is summarized as below -
As other's have stated you could use Replace or Remove with valid inputs.
There is no overload of Remove that takes a char, so the character is implicitly converted to an int and the Remove method tries to use it as an index into the string, which is way outside the string. That's why you get that runtime error instead of a compile time error saying that the parameter type is wrong.
To use Remove to remove part of a string, you first need to find where in the string that part is. Example:
var x = "tesx";
var x = x.Remove(x.IndexOf('x'), 1);
This will remove the first occurance of 'x' in the string. If there could be more than one occurance, and you want to remove all, using Replace is more efficient:
var x = "tesx".Replace("x", String.Empty);
Remove takes an int parameter for the index within the string to start removing characters, see msdn. The remove call must automatically convert the char to its ASCII integer index and try to remove the character at that index from the string, it is not trying to remove the character itself.
If you just want to remove any cases where x occurs in the string do:
"testx".Replace("x",string.Empty);
If you want to remove the first index of x in the string do:
var value = "testx1x2";
var newValue = value.Remove(value.IndexOf('x'), 1);
Since you are passing a char in the function and this value is getting converted to int at runtime hence you are getting the runtime error because the value of char at runtime is more than the length of the string.You may try like this:-
var x = "tesx";
var s = x.Remove(x.IndexOf('x'), 1);
or
var s = x.Replace("x",string.Empty);
.Remove takes the int as parameter. Remove takes two parameters. The first one is what position in your string you want to start at. (The count starts at zero.) The second parameter is how many characters you want to delete, starting from the position you specified.
On a side note:
From MSDN:
This method(.Remove) does not modify the value of the current instance.
Instead, it returns a new string in which the number of characters
specified by the count parameter have been removed. The characters are
removed at the position specified by startIndex.
You can use extension methods to create your own methods for already existing classes. Consider following example:
using System;
using MyExtensions;
namespace ConsoleApplication
{
class Program
{
static void Main(string[] args)
{
const string str1 = "tesx";
var x = str1.RemoveByChar('x');
Console.WriteLine(x);
Console.ReadKey();
}
}
}
namespace MyExtensions
{
public static class StringExtensions
{
public static string RemoveByChar(this String str, char c)
{
return str.Remove(str.IndexOf(c), 1);
}
}
}
int a = Convert.ToInt32(subjectsLabel1.Text);
int b = int.Parse(internetLabel1.Text);
int total = a+b;
label1.Text = total.ToString();
the error "Input string was not in a correct format." keeps poping out.
I tried to convert using the "int.parse" and the "convert.toint32" syntax but the same error keeps showing up.
*the values in the subjectsLabel1 and internetlabel1 would be coming from the database (which was done in visual studio) w/ datatype varchar(10).
There is nothing wrong with the way you are parsing those string values to integers. It's just that their value doesn't represent a valid integer so it cannot be parsed and an exception is thrown. You could use the int.TryParse method to handle gracefully this case:
int a;
int b;
if (!int.TryParse(subjectsLabel1.Text, out a))
{
MessageBox.Show("please enter a valid integer in subjectsLabel1");
}
else if (!int.TryParse(internetLabel1.Text, out b))
{
MessageBox.Show("please enter a valid integer in internetLabel1");
}
else
{
// the parsing went fine => we could safely use the a and b variables here
int total = a + b;
label1.Text = total.ToString();
}
If you're not sure the user is giving you a legal Int32 value to convert you can use:
int result;
if (!int.TryParse(subjectsLabel.Text, out result))
{
ShowAMessageToTheUser();
}
else
{
UseResult();
}
Using TryParse won't trow an exception when you try to parse a string. Instead it will return false and the out parameter is not valid to use.
You Cannot convert to Int32 if the string contains a decimal pointor its not a valid integer .Check
string test = "15.00"
int testasint = Convert.ToInt32(test); //THIS WILL FAIL!!!
Because Int32 does not support decimals. If you need to use decimals, use Float or Double.
So in this situation you can use
int.TryParse
also