Programming PHP

You can use break and continue statements in a do/while statement just as in a normal
while statement.
The do/while statement is sometimes used to break out of a block of code when an
error condition occurs. For example:
do {
// do some stuff
if ($error_condition)
break;
// do some other stuff
} while (false);
Because the condition for the loop is false, the loop is executed only once, regardless
of what happens inside the loop. However, if an error occurs, the code after the
break is not evaluated.
for
The for statement is similar to the while statement, except it adds counter initialization
and counter manipulation expressions, and is often shorter and easier to read
than the equivalent while loop.
Here’s a while loop that counts from 0 to 9, printing each number:
$counter = 0;
while ($counter < 10) {
echo "Counter is $counter\n";
$counter++;
}
Here’s the corresponding, more concise for loop:
for ($counter = 0; $counter < 10; $counter++)
echo "Counter is $counter\n";
The structure of a for statement is:
for (start; condition; increment)
statement
The expression start is evaluated once, at the beginning of the for statement. Each
time through the loop, the expression condition is tested. If it is true, the body of the
loop is executed; if it is false, the loop ends. The expression increment is evaluated
after the loop body runs.
The alternative syntax of a for statement is:
for (expr1; expr2; expr3):
statement;
...;
endfor;
52 | Chapter 2: Language Basics
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