Post your tips for making life easier in C and C++. I'll start:


Standard vector object initialization

The biggest problem with the standard vector class is that one can't use an array initializer. This forces us to do something like this:

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#include <iostream>
#include <vector>

using namespace std;

int main()
{
  vector<int> v;

  v.push_back(1);
  v.push_back(2);
  v.push_back(3);
  v.push_back(4);
  v.push_back(5);

  // Use the vector
}

#include <iostream> #include <vector> using namespace std; int main() { vector<int> v; v.push_back(1); v.push_back(2); v.push_back(3); v.push_back(4); v.push_back(5); // Use the vector }

Anyone who's had the rule of redundancy pounded into their head knows that the previous code could be wrapped in a loop:

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#include <iostream>
#include <vector>

using namespace std;

int main()
{
  vector<int> v;

  for (int i = 1; i < 6; i++)
    v.push_back(i);

  // Use the vector
}

#include <iostream> #include <vector> using namespace std; int main() { vector<int> v; for (int i = 1; i < 6; i++) v.push_back(i); // Use the vector }

However, it's not terribly elegant, especially for a vector of complex types. So, Narue's first timesaving tip for C++ is to use a temporary array so that you can make use of an initializer. Because the vector class defines a constructor that takes a range of iterators, you can use the array to initialize your vector:

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#include <iostream>
#include <vector>

using namespace std;

int main()
{
  int a[] = {1,2,3,4,5};
  vector<int> v(a, a + 5);

  // Use the vector
}

#include <iostream> #include <vector> using namespace std; int main() { int a[] = {1,2,3,4,5}; vector<int> v(a, a + 5); // Use the vector }

I know this may not seem like a super time saving technique, but the way you name your variables will help save time and reduce compile time errors.. Having a conventional variable naming format will help keep things organized and easy to read.

Styles

Typically, most variable names get the every other word capitalized. Functions get the first letter of each word capitalized and constants get all of the letters capitalized.

Example:

Variable: First letter of every other word capitalized.

• char theName[20];

Functions: First letter of each word capitalized .

• void GetTheName();

Constants: All capitals

• #define THENAME 20

Of course, sometimes choosing a good variable name can take a long time!

>Well u can always use STL's "for_each" for efficiency, readability, portability & usability.
for_each isn't nearly as useful as the propaganda suggests. Also, for_each would be a poor solution to the issue that this tip covers. A better solution would be generate_n, but that's still not as concise and easy to follow Consider:

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#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>

using namespace std;

class increment {
  int _i;
public:
  increment(int start = 0): _i(start) {}
  int operator()() { return _i++; }
};

int main()
{
  vector<int> v;

  generate_n(back_inserter(v), 5, increment(1));
  copy(v.begin(), v.end(), ostream_iterator<int>(cout, " "));
  cout<<endl;

  cin.get();
}

#include <algorithm> #include <iostream> #include <iterator> #include <vector> using namespace std; class increment { int _i; public: increment(int start = 0): _i(start) {} int operator()() { return _i++; } }; int main() { vector<int> v; generate_n(back_inserter(v), 5, increment(1)); copy(v.begin(), v.end(), ostream_iterator<int>(cout, " ")); cout<<endl; cin.get(); }

How is that better? You said for_each though, so let's look at that one too. Well, for_each requires a range for the input sequence, so you still need a temporary list, and getting the function to add to a vector isn't as trivial as you seem to think. Instead of suggesting things at random, why don't you try implementing the suggestion first to see how reasonable it is?

>it also make code less readable than the smallCaptialized form..
That's your opinion, and it's debatable.