goto
Image courtesy of » xkcd
The goto operator can be used to jump to another
section in the program. The target point is specified by a case-sensitive label
followed by a colon, and the instruction is given as
goto followed by the desired target label. This
is not a full unrestricted goto. The target
label must be within the same file and context, meaning that you cannot jump
out of a function or method, nor can you jump into one. You also
cannot jump into any sort of loop or switch structure. You may jump
out of these, and a common use is to use a goto
in place of a multi-level break.
Example #1 goto example
<?php
goto a;
echo 'Foo';
a:
echo 'Bar';
?>The above example will output:
Bar
Example #2 goto loop example
<?php
for ($i = 0, $j = 50; $i < 100; $i++) {
while ($j--) {
if ($j == 17) {
goto end;
}
}
}
echo "i = $i";
end:
echo 'j hit 17';
?>The above example will output:
j hit 17
Example #3 This will not work
<?php
goto loop;
for ($i = 0, $j = 50; $i < 100; $i++) {
while ($j--) {
loop:
}
}
echo "$i = $i";
?>The above example will output:
Fatal error: 'goto' into loop or switch statement is disallowed in script on line 2