elseif/else if
(PHP 4, PHP 5, PHP 7, PHP 8)
elseif, as its name suggests, is a combination
of if and else. Like
else, it extends an if
statement to execute a different statement in case the original
if expression evaluates to
false. However, unlike
else, it will execute that alternative
expression only if the elseif conditional
expression evaluates to true. For example, the
following code would display a is bigger than
b, a equal to b
or a is smaller than b:
<?php
if ($a > $b) {
echo "a is bigger than b";
} elseif ($a == $b) {
echo "a is equal to b";
} else {
echo "a is smaller than b";
}
?>
There may be several elseifs within the same
if statement. The first
elseif expression (if any) that evaluates to
true would be executed. In PHP, you can also
write 'else if' (in two words) and the behavior would be identical
to the one of 'elseif' (in a single word). The syntactic meaning
is slightly different (if you're familiar with C, this is the same
behavior) but the bottom line is that both would result in exactly
the same behavior.
The elseif statement is only executed if the
preceding if expression and any preceding
elseif expressions evaluated to
false, and the current
elseif expression evaluated to
true.
Note: Note that
elseifandelse ifwill only be considered exactly the same when using curly brackets as in the above example. When using a colon to define yourif/elseifconditions, you must not separateelse ifinto two words, or PHP will fail with a parse error.
<?php
/* Incorrect Method: */
if ($a > $b):
echo $a." is greater than ".$b;
else if ($a == $b): // Will not compile.
echo "The above line causes a parse error.";
endif;
/* Correct Method: */
if ($a > $b):
echo $a." is greater than ".$b;
elseif ($a == $b): // Note the combination of the words.
echo $a." equals ".$b;
else:
echo $a." is neither greater than or equal to ".$b;
endif;
?>
