The code below is part of an algorithm that shows the height of a binary tree:
int left = height(p->left);
int right= height(p->right);
int larger = (left > right? left : right);
return 1 + larger;
What does this part (left > right? left : right) mean?
> means greater than, equal in all languages and math (although it is usually a statement and in programming it is a question that will generate a Boolean result, in which case you are asking if the value of left is greater than the value of right .
The result will decide what to do with the next operator that is ternary (currently the only one so), ie it has three parts. His name is conditional operator . Then the value of the second part (after ? will be the result of every expression if the previous condition is true. If false the result will be the last part, that is, after : . saved in larger .
So it's like a if , but it's an expression.
This code could be written like this:
int left = height(p->left);
int right= height(p->right);
if (left > right) return 1 + left;
else return 1 + right
I placed GitHub for future reference .
The equivalence of this would be:
int larger;
if(left > right){
larger = left;
}else{
larger = right;
}
The name of this code statement:
int larger = (left > right? left : right);
is called Ternary Conditional Instruction.
int larger = (left > right ? left : right)
In simple mode
(condição ? verdadeiro : falso)
before ? would be the condition and between : the answer