help with if n condition evaluation

i have seen at many places where condition is to be evaluated..
if(a)
{}
if(!a)
{}
for(i=0;!a;i++)
{}
if(1){}
if(!9){}

and things lyk that

can u tell me wat r the various types of conditions of if() n wat datatypes should be "a" for the above cases...???
and i knw the basic functionality of if()..!!!

 

In C language sir..

 

Hello IndiraP

Suppose I have the following

Code:

int a=5
if(a)
...

What would such absurd looking loc(lines of code) mean?Well if you look at it closely it means "If the a has a definite value(any value other than zero) then the condition is true else the condition is false".Even a negative value or a floating point value is taken as truth value.

 

Thank u ..