Why is a assigned the value 3? Does the compiler simply take the last value from the list?
int a;
a=(1,2,3);
printf("%d",a);
How does compiler parse this statement or how it works internally?
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1See http://en.wikipedia.org/wiki/Comma_operator. – AlexD Sep 28 '14 at 06:11
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Read about comma operator in C. – ani627 Sep 28 '14 at 06:11
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because `,`(comman) is an operator so last value will be assigned to a. – Rustam Sep 28 '14 at 06:13
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[How does the Comma Operator work](http://stackoverflow.com/questions/54142/how-does-the-comma-operator-work) – ani627 Sep 28 '14 at 06:20
2 Answers
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Comma in (1,2,3) is a comma operator. It is evaluated as
a = ( (1,2) ,3 );
Comma operator is left associative. The result/value of the expression (1,2,3) is the value of the right operand of comma operator.
haccks
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As pointed out in the comments, it's because you're using the comma operator. That means the 1 and 2 are evaluated and discarded. The three is the only thing left to be assigned. Without the parenthesis it would most likely be assigned as 1.
Sunjay Varma
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