This is what a loop is:

first off: pouya: come on, the guys making an honest effort!

now, do get yourself a compiler as suggested by LessBread. If you find that explanation lacking and can''t understand the one in your book you could try this tutorial. The top of the page is about if statements, but farther down it gets to loops. You could also try looking at the rest of the tutorial that that page comes from.

Finally, I don''t know about lccwin32, but Dev-C++ is an ide, not compiler, but you will most likely want the ide as well as the compiler. However, you could also get away with just mingw (i''m assuming windows) and a text editor.

pouya, that''s a nasty thing to give a beginner; you''ll confuse the hell out of him!

Mage_gr, a loop in programming is a sequence of instructions/operations that are pefromed several times in order, until a specific exit condition has been reached. There are two basic looping constructs in programming, which are functionally equivalent - for loops and while loops.

Assuming your programming language to be C/C++ or any syntactically similar language (Java, Perl to an extent), for loops look like this:

for( expr1; expr2; expr3 )  statement_block 

expr1 is typically a statement that initializes a loop counter, expr2 is often a conditional statement that tests for the exit condition and expr3 is a post execution statement, usually counter increment:

for( int n = 0; n < MAX_N; ++n)  statement_block 

It''s important to note that none of these statements is mandatory in C-like languages. You may come across perfectly valid loops that look like this:

for( ; ; )  statement_block 

In such cases statement_block will perform the loop management.

while loops execute just like for loops, except that they have a little less syntactic sugar:

while( condition )  statement_block 

Once condition becomes false, the loop terminates. You can therefore think of a for loop as being equivalent to the following while loop:

expr1;while( expr2 ){  statement_block;  expr3;} 

The final piece of the puzzle - statement_block. In C-like languages, the body of a for or while loop (or an if statement) can only be a single statement. To get around this, however, statements can be blocked together using the curly braces {} and appear as a single statement to code at higher scopes. That allows us to write the following:

while( true ){  CallSomeFunction();  if( SomeConditionTest() == SomeVal )    break;} 

Wait a sec... what''s that break thingie? The break keyword exits the smallest enclosing for, while or switch statement. That means that in the code above, the break statement will exit the loop if SomeConditionTest returns SomeVal. Look, Ma! No counters!

The corollary to the break statement is the continue statement, which advances to the next iteration of a loop construct. Here''s an example:

while( true ){  SomeVar = CallSomeInitFunction();  if( SomeConditionTest( SomeVar ) == SomeVal )    continue;  if( SomeOtherConditionTest( SomeVar == SomeOtherVal )    break;  // the code following only executes for values that "pass" both tests  SomeFunction();} 

Hopefully, that explained loops in a generic, robust and accessible way.

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Thanks to Kylotan for the idea!