CODEWITHSUNDEEP
c#
user1618825
user1618825

Reputation:

string not converting to integer

I am trying to convert string to integer from a object's property, where i am facing lot of problems.

1st Method

public class test
{
    public string Class { get; set; }
}

//test.Class value is 150.0
var i = Convert.ToInt32(test.Class);

It is saying error that Input String is not in a correct format

2nd Method

int i = 0;
Int32.TryParse(test.Class, out i);

The value of the above code is always zero

3rd Method

int j = 0;
Int32.TryParse(test.Class, NumberStyles.Number, null, out j);

Here i am getting the value as 150 correctly but as I am using null for IFormatProvider Will there be any problem with this?

Which is the proper method for converting string to integer with these cases?

Upvotes: 2

Views: 875

Answers (4)

Dmitrii Bychenko
Dmitrii Bychenko

Reputation: 186688

The value 150.0 includes decimal separator "." and so can't be converted directly into any integer type (e.g. Int32). You can obtain the desired value in two stage conversion: first to double, then to Int32

Double d;

if (Double.TryParse(test.Class, NumberStyles.Any, CultureInfo.InvariantCulture, out d)) {
  Int32 i = (Int32) d;
  // <- Do something with i
}
else {
  // <- test.Class is of incorrect format
}

Upvotes: 1

Mataniko
Mataniko

Reputation: 2232

As others have said, you can't convert a 150.0 to an integer, but you can convert it to a Double/Single and then cast it to int.

int num = (int)Convert.ToSingle(test.Class) //explicit conversion, loss of information

Source: http://msdn.microsoft.com/en-us/library/sf1aw27b.aspx

Upvotes: 0

sweeneypng
sweeneypng

Reputation: 1

From the MSDN documentation: you get a FormatException if "value does not consist of an optional sign followed by a sequence of digits (0 through 9)". Lose the decimal point, or convert to a float and then convert to int.

Upvotes: 0

Rajeev Kumar
Rajeev Kumar

Reputation: 4963

If you sure that test.class contains float value than better use this

float val= Convert.ToSingle(test.class, CultureInfo.InvariantCulture);

Convert.ToInt32("150.0") Fails Because It is simply not an integer as the error says quite handsomly

Upvotes: 1

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