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?? Null Coalescing Operator --> What does coalescing mean?
What do two question marks together mean in C#?
I couldn't find this question being asked here so I figured I would ask it. What does a double question mark do in C#?
Example:
x = y ?? z; 
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If double question marks are uses it is to emphasise something in return, usually from the shock of the previous thing said. For example, if I said: 'My dog just died' (sad, but used for example...)
The C# double question mark operator ?? is called the null-coalescing operator. It is used to return the left hand side operand of the operator if the value is not null and the right hand side operand if the value is null.
Most likely the '?' is the ternary operator. Its grammar is: RESULT = (COND) ? ( STATEMEN IF TRUE) : (STATEMENT IF FALSE) It is a nice shorthand for the typical if-else statement: if (COND) { RESULT = (STATEMENT IF TRUE); } else { RESULT = (STATEMENT IF FALSE);
The question mark operator, ?:, is also found in C++. Some people call it the ternary operator because it is the only operator in C++ (and Java) that takes three operands. If you are not familiar with it, it's works like an if-else, but combines operators.
This is a null coalescing operator. The method above states x is assigned y's value, unless y is null, in which case it is assigned z's value.
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From Wikipedia:
It's the null-coalesce operator and shorthand for this:
x = (y != null ? y : z); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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