php中常用的数组操作函数(1/8)

$usernames = array ('Alerk', 'Mary', 'Lucy', 'Bob', 'Jack', 'John', 'Mark' );
foreach ( $usernames as $name )
{
echo $name . '
';
}
?>

output
Alerk
Mary
Lucy
Bob
Jack
John
Mark

$numbers = range ( 0, 10 );
foreach ( $numbers as $num )
{
echo $num . '
';
}
$letters = range ( 'a', 'z' );
foreach ( $letters as $letter )
{
echo $letter . '
';
}
?>

output
0
1
2
3
4
5
6
7
8
9
10
a

c
d
e
f
g
h
i
j
k
l
m

o

q
r

t
u
v
w
x
y
z

//range的第三个参数表示步长
$numbers = range(1,10,2);
for($i = 0;$i {
echo $numbers[$i].'
';
}
?>

output
1
3
5
7
9