PHP arrays (array) output of three forms of detailed _php tips

Copy Code code as follows:

$BBBB =array ("One" => "AAA", "=>" "BBB");
can only output values value cannot output key
foreach ($bbbb as $color)
{
Echo $color;
}
Both value and key can be exported
foreach ($bbbb as $key => $value)
{
echo $key. " => ". $value;
}

Both value and key can be exported
while ($color =each ($bbbb)) {
echo $color [' key '];
}
Or
while (list ($key, $value) =each ($BBBB)) {
echo "$key: $value <br>";
}

To access an array element directly:

Copy Code code as follows:

<?php
$arr =array (' W ' => ' Wen ', ' j ' => ' Jian ', ' B ' => ' Bao ');
Echo ($arr [' W ']), ' <br/> '/function
Echo ($arr [w]), ' <br/> '/function
Echo ($arr [0]), ' <br/> '/does not work, do not know why???
Echo ($arr [' J ']), ' <br/> '/function
Echo ($arr [j]), ' <br/> '/function
Echo ($arr [1]), ' <br/> '/does not work, do not know why???
Echo ($arr [' B ']), ' <br/> '/function
Echo ($arr [b]), ' <br/> '/function
Echo ($arr [2]), ' <br/> '/does not work, do not know why???
?>

Output:

Copy Code code as follows:

Wen
Wen
Jian
Jian
Bao
Bao

Doubtful points:
To access an associative array element,
1, [] in the "key" can be used without quotation marks ("") is also accessible???
2, the array index Access does not work???

Copy Code code as follows:

<?php
$arr 1=array (' Wen ', ' Jian ', ' bao ');
Echo $arr 1[0], ' <br/> ', $arr 1[1], ' <br/> ', $arr 1[2];
?>

Output:

Copy Code code as follows:

Wen
Jian
Bao