Array
(
    [0] => 
    [1] => abc
    [2] => de
    [3] => efg
    [4] => 
)
Array
(
    [0] => abc
    [1] => de
    [2] => efg
)
Array
(
    [0] => hypertext
    [1] => language
    [2] => programming
    [3] => 事例
    [4] => preg_split関数
)
Array
(
    [0] => s
    [1] => t
    [2] => r
    [3] => i
    [4] => n
    [5] => g
)
Array
(
    [0] => Array
        (
            [0] => hypertext
            [1] => 0
        )

    [1] => Array
        (
            [0] => language
            [1] => 10
        )

    [2] => Array
        (
            [0] => programming
            [1] => 19
        )

)