C/C++: what is the difference between for loop and while loop except its syntax?

Answer 1

The main difference between while() and for() loop is when you use continue with them.
If continue is used before the increment of a variable is done it converts while() loop into a infinite loop.

Lets see an example.

i=1;
while(i < 10) {
     /* statements */
     if(i == 5);
         continue;
     i++;
}
//The above piece of code will turn into an infinite loop.

for(i = 1;  i < 10;  i++) {
      /* statements */
      if(i == 5);
          continue;
}
//Here in for loop the value of will be incremented once it attains the value of 5.
//Therefore it will not turn into a infinite loop. 

Beside those differences, you can use for() loop as a while() loop.

for(  ; condition;   )  /* exactly same as */
while(condition)

Answer 2

We normally use "for" when there is a known number of iterations and use "while" when number of iterations in not known before hand.