Description
void
list ( mixed ...)
Like
array(), this is not really a function, but a
language construct. list() is used to
assign a list of variables in one operation.
注: list() only works on
numerical arrays and assumes the numerical indices start
at 0.
範例 1. list()
examples
?php
$info = array('coffee', 'brown', 'caffeine');
// Listing all the variables
list($drink, $color, $power) = $info;
print "$drink is $color and $power makes it special.\n";
// Listing some of them
list($drink, , $power) = $info;
print "$drink has $power.\n";
// Or let's skip to only the third one
list( , , $power) = $info;
print "I need $power!\n";
?
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範例 2. An example use of
list()
table
tr
th Employee name /th
th Salary /th
/tr
?php
$result = mysql_query ("SELECT id, name, salary FROM employees",$conn);
while (list ($id, $name, $salary) = mysql_fetch_row ($result)) {
print (" tr \n".
" td a href=\"info.php?id=$id\" $name /a /td \n".
" td $salary /td \n".
" /tr \n");
}
?
/table
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警告 |
list() assigns the
values starting with the right-most parameter. If you
are using plain variables, you don't have to worry
about this. But if you are using arrays with indices
you usually expect the order of the indices in the
array the same you wrote in the
list() from left to right; which it isn't. It's
assigned in the reverse order.
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範例 3. Using list() with
array indices
?php
$info = array('coffee', 'brown', 'caffeine');
list($a[0], $a[1], $a[2]) = $info;
var_dump($a);
?
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Gives the following output (note the order of the elements
compared in which order they were written in the
list() syntax):
array(3) {
[2]=
string(8) "caffeine"
[1]=
string(5) "brown"
[0]=
string(6) "coffee"
}
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See also each(), array() and
extract().