Ds\Sequence::first

(PECL ds >= 1.0.0)

Ds\Sequence::first — Returns the first value in the sequence

說明

abstract public Ds\Sequence::first(): mixed

Returns the first value in the sequence.

參數(shù)

此函數(shù)沒有參數(shù)。

返回值

The first value in the sequence.

錯(cuò)誤／異常

UnderflowException if empty.

范例

示例 #1 Ds\Sequence::first() example

<?php
$sequence = new \Ds\Vector([1, 2, 3]);
var_dump($sequence->first());
?>

以上例程的輸出類似于：

int(1)