Is this an if else statement

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What do two question marks together mean in C#?

I just came across the code below and not really sure what it means and can't google it because google omits the ??

int? x = 32;
int  y = x ?? 5;

Is the second line some sort of if else statement, what does the ?? mean

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It's called the null-coalescing operator.

If the value to the left of the ?? is null , then use the value to the right of the ?? otherwise use the left hand value.

Expanded out:

y = x == null ? 5 : x

or

if(x == null)
     y = 5
else
     y = x

---

if(x == null)
     y = 5
else
     y = x

---

The ?? operator is used with a collection of variables and evaluates to the value of the first non-null variable. For example, consider the following code:

int? x = null;
int? y = null;
int? z = null;

y = 12;
int? a = x ?? y ?? z;

The value of a will be 12, because y is the first variable in the statement with a non-null value.

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