If statement with ? and : [duplicate]

Answer 1

?: is ternary operator in C (also called conditional operator). You can shorten your code like

if(condition)
    expr1;
else
    expr2;  

to

condition ? expr1 : expr2;   

See how it works:

C11: 6.5.15 Conditional operator:

The first operand is evaluated; there is a sequence point between its evaluation and the evaluation of the second or third operand (whichever is evaluated). The second operand is evaluated only if the first compares unequal to 0; the third operand is evaluated only if the first compares equal to 0; the result is the value of the second or third operand (whichever is evaluated),