本文整理匯總了PHP中Arr::previous_by_key方法的典型用法代碼示例。如果您正苦於以下問題：PHP Arr::previous_by_key方法的具體用法？PHP Arr::previous_by_key怎麽用？PHP Arr::previous_by_key使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類Arr的用法示例。
在下文中一共展示了Arr::previous_by_key方法的2個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的PHP代碼示例。
示例1: test_previous_by_key
/**
* Tests Arr::previous_by_key()
*
* @test
*/
public function test_previous_by_key()
{
// our test array
$arr = array(2 => 'A', 4 => 'B', 6 => 'C');
// test: key not found in array
$expected = false;
$test = \Arr::previous_by_key($arr, 1);
$this->assertTrue($expected === $test);
// test: no previous key
$expected = null;
$test = \Arr::previous_by_key($arr, 2);
$this->assertTrue($expected === $test);
// test: strict key comparison
$expected = false;
$test = \Arr::previous_by_key($arr, '2', false, true);
$this->assertTrue($expected === $test);
// test: get previous key
$expected = 2;
$test = \Arr::previous_by_key($arr, 4);
$this->assertTrue($expected === $test);
// test: get previous value
$expected = 'A';
$test = \Arr::previous_by_key($arr, 4, true);
$this->assertTrue($expected === $test);
}示例2: convert_img_size_down
public static function convert_img_size_down($size, $type = 'm')
{
$size = strtoupper($size);
$sizes = conf('upload.types.img.types.' . $type . '.sizes');
if (!array_key_exists($size, $sizes)) {
return false;
}
return Arr::previous_by_key($sizes, $size);
}