CODEWITHSUNDEEP
c++
peter--
peter--

Reputation: 3

c++ semicolon - what are the rules for loops and statements?

I'm learning C++ and generally it has good and clear rules - but I'm a little confused about the rules related to semicolon. The following two examples are working fine - but what is the best practice - and what is the logic behind it?

Example1 (without semicolon):

#include <iostream>
using namespace std;

int main () {
    for (int i = 0; i < 10; i++) {
        if (true) {
            cout << i << endl;
        }

    }
}

Example2 (with 3x semicolon):

#include <iostream>
using namespace std;

int main () {
    for (int i = 0; i < 10; i++) {
        if (true) {
            cout << i << endl;
        };

    };
};

Upvotes: 0

Views: 92

Answers (1)

paxdiablo
paxdiablo

Reputation: 882098

Example 2, reformatted:

#include <iostream>
using namespace std;

int main () {
    for (int i = 0; i < 10; i++) {
        if (true) {
            cout << i << endl;
        }
        /*do nothing*/ ;
    }
    /*do nothing*/ ;
}
/*do nothing*/ ;

In other words, ; in this case is simply an empty statement, totally superfluous. It's legal, but about as useful as the statement 42;, which is also legal :-)

However, it can sometimes be useful in things like (one example of many), though I usually prefer the {} construct in these cases:

while (performAction(var++)) ;

Upvotes: 1

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