The ? (ternary condition) operator is a more efficient form for expressing simple if statements. It has the following form:
expression1 ? expression2 : expression3
It simply states:
if expression1 is true then do expression2 ,in any other case do expression3
For example to assign the maximum of a and b to z:
z = (a>b) ? a: b;
which is the same as:
if (a>b) {
z=a;
} else {
z=b;
}