typedef Related doubts?

[rajeshs]

Hi All,

I am fresher to C++ programming, I want to know about why we need typedef ?

now i am thinking it's only for programmers convinience , any other performance reasons

please share your ideas,

and i read in one tutorial about function alias using typedef as follows,

typedef double (*Addition)(double value1, double value2);

double Add(double x, double y)
{
double result = x + y;
return result;
}

Usage:

Addition plus;

plus =Add;

double ans = plus(3855.06, 74.88);

In which suituations this kind

of typedef for function alias will be helpful ?

please help me to learn the typedef ?

If you know any tutorial or books to learn usage of C++ concepts please let me know?

[jacek]

In which suituations this kind

of typedef for function alias will be helpful ?

You use typedef to:

• avoid errors by simplifying complex declarations,
• avoid repetition,
• provide meaningful type names and hide implementation details (for example iterator instead of node *).

If you know any tutorial or books to learn usage of C++ concepts please let me know?

See here: http://www.qtcentre.org/forum/f-gene...-books-29.html

[rajeshs]

Thank you very much for your valuable reply,

now i am getting to know about typedef

If any body knows about advantages of using function pointers please help me?

[jacek]

If any body knows about advantages of using function pointers please help me?

Function pointers are used when a value isn't enough --- you can use them to pass around different behaviours. The classic examples are qsort() and callbacks. In OO world, FP were replaced by functional objects (a.k.a. functors).