Returns the timestamp component of this ObjectId

# MongoDB\BSON\ObjectId::getTimestamp

(mongodb >=1.2.0)

MongoDB\BSON\ObjectId::getTimestamp — Returns the timestamp component of this ObjectId

### 説明

final public MongoDB\BSON\ObjectId::getTimestamp ( void ) : int

The timestamp component of an ObjectId is its most significant 32 bits, which denotes the number of seconds since the Unix epoch. This value is read as an unsigned 32-bit integer with big-endian byte order.

> 注意: Because PHP's integer type is signed, some values returned by this method may appear as negative integers on 32-bit platforms. The "%u" formatter of sprintf() may be used to obtain a string representation of the unsigned decimal value.

### パラメータ

この関数にはパラメータはありません。

### 返り値

Returns the timestamp component of this ObjectId.

### エラー / 例外

- 引数のパースに失敗した場合に MongoDB\Driver\Exception\InvalidArgumentException をスローします。

### 例

例1 MongoDB\BSON\ObjectId::getTimestamp() example

`<?php
var_dump((new MongoDB\BSON\ObjectId())->getTimestamp());
var_dump((new MongoDB\BSON\ObjectId('0000002a0000000000000000'))->getTimestamp());
?>`

上の例の出力は、 たとえば以下のようになります。

    integer(1484854719)
    integer(42)

### 参考

- » ObjectId Reference
- » BSON Types: ObjectId