Programmers use the ternary operator for decision making in place of longer if and else conditional statements.
The ternary operator take three arguments:
- The first is a comparison argument
- The second is the result upon a true comparison
- The third is the result upon a false comparison
It helps to think of the ternary operator as a shorthand way or writing an if-else statement. Here’s a simple decision-making example using if and else:
int a = 10, b = 20, c;
if (a < b) {
c = a;
}
else {
c = b;
}
printf("%d", c);
This example takes more than 10 lines, but that isn’t necessary. You can write the above program in just 3 lines of code using a ternary operator.
Syntax
condition ? value_if_true : value_if_false
The statement evaluates to value_if_true
if condition
is met, and value_if_false
otherwise.
Here’s the above example rewritten to use the ternary operator:
int a = 10, b = 20, c;
c = (a < b) ? a : b;
printf("%d", c);
Output of the example above should be:
10
c
is set equal to a
, because the condition a < b
was true.
Remember that the arguments value_if_true
and value_if_false
must be of the same type, and they must be simple expressions rather than full statements.
Ternary operators can be nested just like if-else statements. Consider the following code:
int a = 1, b = 2, ans;
if (a == 1) {
if (b == 2) {
ans = 3;
} else {
ans = 5;
}
} else {
ans = 0;
}
printf ("%d\n", ans);
Here's the code above rewritten using a nested ternary operator:
int a = 1, b = 2, ans;
ans = (a == 1 ? (b == 2 ? 3 : 5) : 0);
printf ("%d\n", ans);
The output of both sets of code above should be:
3