What is the proper way to check for null values?

Question

I love the null-coalescing operator because it makes it easy to assign a default value for nullable types.

 int y = x ?? -1;

That\'s great,

Answer 1

Skeet's answer is the best - in particularly I think his ToStringOrNull() is quite elegant and suits your need best. I wanted to add one more option to the list of extension methods:

Return original object or default string value for null:

// Method:
public static object OrNullAsString(this object input, string defaultValue)
{
    if (defaultValue == null)
        throw new ArgumentNullException("defaultValue");
    return input == null ? defaultValue : input;
}

// Example:
var y = Session["key"].OrNullAsString("defaultValue");

Use var for the returned value as it will come back as the original input's type, only as the default string when null