CODEWITHSUNDEEP
c++coperator-precedence
Jainendra
Jainendra

Reputation: 25143

Precedence order of function execution in C

What is the execution sequence of the following statement:

x = f(2) * g(5) + h();

I have seen this link, the precedence order should be f, g and h. Am I right or not, please explain

Upvotes: 2

Views: 818

Answers (2)

chux
chux

Reputation: 153407

With x = f(2) * g(5) + h();
f(2), g(5) and h() are executed in any sequence - perhaps even simultaneous if the processor supports such.

The results of f() and g() are multiplied. That product is then added to the result of h().

Upvotes: 3

user123
user123

Reputation: 9071

In this case, you can't make any guarantees about the order of execution of the functions.

While precedence rules imply that f(2) will be multiplied by g(5) before h() is added to the result, the order of execution of these sub-expressions is implementation-defined.

If you're doing this with functions that have side-effects, don't. Depending on the code, you may or may not see different results from compiler to compiler.

Note: As @Jakub Zaverka mentions, there are slightly different rules when you're dealing with logical operators && or || because of features like short-circuiting.

Upvotes: 7

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