On Wed, 16 Jan 2002, Abhir Joshi wrote:
In the source code of some packages, I have seen 'for (;;)' where 'while (1)' could have done the job. Is it related to the efficiency of the code generated ? I have also seen that the a java
There is no difference between a while loop and a for loop. Both are entry controlled, both test for a condition. The difference is for has an extra statement executed before the loop entry, and at the end of the loop. If these two do not exist, the for and while are identical. So:
while(condition) == for(;condition;)
when they are compiled, both are converted to this algorithm in machine language:
initialise loop variable (for only) LOOP_START: check condition jnz LOOP_END do something change loop variable (for only) goto LOOP_START LOOP_END:
A do{}while loop is different though. The condition is checked on exit:
LOOP_START: do something check condition jz LOOP_START
As you can see, after compiling, there is no for, no while, no do{}while. Just if and goto.
To make your programs faster, replace all for, while, do loops with an if - goto construct. <evil grin>