What is the execution logic of the expression in C?

Question

Suppose I a couple of expression in C. Different outputs are provided.

int i =2,j;
j= i + (2,3,4,5);
printf("%d %d", i,j);
//Output= 2 7

 j= i + 2,3,4,5;
 printf("%d %d", i,j);
 //Output 2 4

How does the execution take place in both expression with and without bracket giving different outputs.

score 4 · Accepted Answer · answered Aug 21 '17 at 04:41

Comma operator works by evaluating all expressions and returning the last expression.

j= i + (2,3,4,5);

becomes

j= i + (5); //j=7

In the second expression assignment operator takes precedence over comma operator,so

j= i + 2,3,4,5;

becomes

(j= i + 2),3,4,5; //j=4

1 Answers1