基本 関数 返り値
たまに間違えて使ってそうな関数の一覧まとめ
//トレース値
$list = array( "", NULL, "0", 0, "1", 1, "1.5", 1.5, FALSE, TRUE,
array(), array(NULL), array("0"), array(0), array("1"), array(1),
array(FALSE), array(TRUE),
'A',' ',' ' );
| 関数 | トレース値 | 返り値 |
| is_null | '' | false |
|---|---|---|
| NULL | true | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_int | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | true | |
| '1' | false | |
| 1 | true | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_float | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | true | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_numeric | '' | false |
| NULL | false | |
| '0' | true | |
| 0 | true | |
| '1' | true | |
| 1 | true | |
| '1.5' | true | |
| 1.5 | true | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_nan | '' | NULL |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | NULL | |
| array ( 0 => NULL,) | NULL | |
| array ( 0 => '0',) | NULL | |
| array ( 0 => 0,) | NULL | |
| array ( 0 => '1',) | NULL | |
| array ( 0 => 1,) | NULL | |
| array ( 0 => false,) | NULL | |
| array ( 0 => true,) | NULL | |
| 'A' | NULL | |
| ' ' | NULL | |
| ' ' | NULL | |
| is_string | '' | true |
| NULL | false | |
| '0' | true | |
| 0 | false | |
| '1' | true | |
| 1 | false | |
| '1.5' | true | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | true | |
| ' ' | true | |
| is_object | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_bool | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | true | |
| true | true | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_finite | '' | NULL |
| NULL | true | |
| '0' | true | |
| 0 | true | |
| '1' | true | |
| 1 | true | |
| '1.5' | true | |
| 1.5 | true | |
| false | true | |
| true | true | |
| array () | NULL | |
| array ( 0 => NULL,) | NULL | |
| array ( 0 => '0',) | NULL | |
| array ( 0 => 0,) | NULL | |
| array ( 0 => '1',) | NULL | |
| array ( 0 => 1,) | NULL | |
| array ( 0 => false,) | NULL | |
| array ( 0 => true,) | NULL | |
| 'A' | NULL | |
| ' ' | NULL | |
| ' ' | NULL | |
| is_infinite | '' | NULL |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | NULL | |
| array ( 0 => NULL,) | NULL | |
| array ( 0 => '0',) | NULL | |
| array ( 0 => 0,) | NULL | |
| array ( 0 => '1',) | NULL | |
| array ( 0 => 1,) | NULL | |
| array ( 0 => false,) | NULL | |
| array ( 0 => true,) | NULL | |
| 'A' | NULL | |
| ' ' | NULL | |
| ' ' | NULL | |
| is_array | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | true | |
| array ( 0 => NULL,) | true | |
| array ( 0 => '0',) | true | |
| array ( 0 => 0,) | true | |
| array ( 0 => '1',) | true | |
| array ( 0 => 1,) | true | |
| array ( 0 => false,) | true | |
| array ( 0 => true,) | true | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| _empty | '' | true |
| NULL | true | |
| '0' | true | |
| 0 | true | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | true | |
| true | false | |
| array () | true | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| _isset | '' | true |
| NULL | false | |
| '0' | true | |
| 0 | true | |
| '1' | true | |
| 1 | true | |
| '1.5' | true | |
| 1.5 | true | |
| false | true | |
| true | true | |
| array () | true | |
| array ( 0 => NULL,) | true | |
| array ( 0 => '0',) | true | |
| array ( 0 => 0,) | true | |
| array ( 0 => '1',) | true | |
| array ( 0 => 1,) | true | |
| array ( 0 => false,) | true | |
| array ( 0 => true,) | true | |
| 'A' | true | |
| ' ' | true | |
| ' ' | true | |
| is_resource | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| is_scalar | '' | true |
| NULL | false | |
| '0' | true | |
| 0 | true | |
| '1' | true | |
| 1 | true | |
| '1.5' | true | |
| 1.5 | true | |
| false | true | |
| true | true | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | true | |
| ' ' | true | |
| _if | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | true | |
| 1 | true | |
| '1.5' | true | |
| 1.5 | true | |
| false | false | |
| true | true | |
| array () | false | |
| array ( 0 => NULL,) | true | |
| array ( 0 => '0',) | true | |
| array ( 0 => 0,) | true | |
| array ( 0 => '1',) | true | |
| array ( 0 => 1,) | true | |
| array ( 0 => false,) | true | |
| array ( 0 => true,) | true | |
| 'A' | true | |
| ' ' | true | |
| ' ' | true | |
| _array_search | '' | 0 |
| NULL | 0 | |
| '0' | 2 | |
| 0 | 0 | |
| '1' | 4 | |
| 1 | 4 | |
| '1.5' | 6 | |
| 1.5 | 6 | |
| false | 0 | |
| true | 4 | |
| array () | 1 | |
| array ( 0 => NULL,) | 9 | |
| array ( 0 => '0',) | 9 | |
| array ( 0 => 0,) | 9 | |
| array ( 0 => '1',) | 9 | |
| array ( 0 => 1,) | 9 | |
| array ( 0 => false,) | 9 | |
| array ( 0 => true,) | 9 | |
| 'A' | 3 | |
| ' ' | 3 | |
| ' ' | 3 | |
| ctype_alnum | '' | false |
| NULL | false | |
| '0' | true | |
| 0 | false | |
| '1' | true | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | false | |
| ' ' | false | |
| ctype_alpha | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | false | |
| ' ' | false | |
| ctype_cntrl | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | true | |
| '1' | false | |
| 1 | true | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| ctype_digit | '' | false |
| NULL | false | |
| '0' | true | |
| 0 | false | |
| '1' | true | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| ctype_graph | '' | false |
| NULL | false | |
| '0' | true | |
| 0 | false | |
| '1' | true | |
| 1 | false | |
| '1.5' | true | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | false | |
| ' ' | false | |
| ctype_lower | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| ctype_print | '' | false |
| NULL | false | |
| '0' | true | |
| 0 | false | |
| '1' | true | |
| 1 | false | |
| '1.5' | true | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | true | |
| ' ' | false | |
| ctype_punct | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | false | |
| ' ' | false | |
| ctype_space | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | false | |
| ' ' | true | |
| ' ' | false | |
| ctype_upper | '' | false |
| NULL | false | |
| '0' | false | |
| 0 | false | |
| '1' | false | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | false | |
| ' ' | false | |
| ctype_xdigit | '' | false |
| NULL | false | |
| '0' | true | |
| 0 | false | |
| '1' | true | |
| 1 | false | |
| '1.5' | false | |
| 1.5 | false | |
| false | false | |
| true | false | |
| array () | false | |
| array ( 0 => NULL,) | false | |
| array ( 0 => '0',) | false | |
| array ( 0 => 0,) | false | |
| array ( 0 => '1',) | false | |
| array ( 0 => 1,) | false | |
| array ( 0 => false,) | false | |
| array ( 0 => true,) | false | |
| 'A' | true | |
| ' ' | false | |
| ' ' | false |
