CODEWITHSUNDEEP
c#
Mithrilhall
Mithrilhall

Reputation: 1502

Operator '??' cannot be applied to operands of type 'string' and 'int'

I'm having trouble getting 'Year' to be a default value of the current Year if there is no value.

var now = DateTime.Now;
Year = int.Parse(bindingContext.ValueProvider.GetValue("Year").AttemptedValue ?? now.Year);

Upvotes: 2

Views: 4395

Answers (4)

sll
sll

Reputation: 62564

It seems that 

bindingContext.ValueProvider.GetValue("Year").AttemptedValue

is of string type,?? operator expect both left/right values are of the same type.

As a case you can do now.Year.ToString():

var now = DateTime.Now;
Year = int.Parse(
             bindingContext.ValueProvider.GetValue("Year").AttemptedValue 
             ?? now.Year.ToString());

Upvotes: 2

viggity
viggity

Reputation: 15237

You have to apply the coalesce operator on two like types. String and int are not the same. Try this instead:

var year = 0;
if(!int.TryParse(bindingContext.ValueProvider.GetValue("Year").AttemptedValue, out year))
    year = DateTime.Now.Year;

In the example, year will only be replaced if the AttemptedValue is parsable into an integer, otherwise it'll be the current year.

Upvotes: 7

Curtis
Curtis

Reputation: 103428

Use .ToString():

Year = int.Parse(bindingContext.ValueProvider.GetValue("Year").AttemptedValue ?? now.Year.ToString());

Both variables need to be of the same type.

Upvotes: 2

Gaz Winter
Gaz Winter

Reputation: 2989

The problem is that one of your values is a string and one is an int therefore it cannot decide what to convert too

You need to make sure that the types match and this problem should go away.

I would use .ToString() so that they are both strings.

Upvotes: 0

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