is_int()和ctype_digit()之间有区别吗？

Question

是一个更优先,还是比另一个更好？

Answer 1

is_int()如果参数是整数类型,ctype_digit()则返回true,如果字符串中的所有字符都是数字,则返回字符串参数并返回true.

例:

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?          ?  is_int:  ?  ctype_digit:  ?
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? 123      ?  true     ?  false         ?
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? 12.3     ?  false    ?  false         ?
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? "123"    ?  false    ?  true          ?
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? "12.3"   ?  false    ?  false         ?
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? "-1"     ?  false    ?  false         ?
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? -1       ?  true     ?  false         ?
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Answer 2

is_numeric如果传入的值可以解析为数字，则还有返回 true 。

如果我尝试在PHP 5.5.30上比较函数的性能，结果如下：

这是我用于基准测试的代码

// print table cell and highlight if lowest value is used
function wr($time1, $time2, $time3, $i) {
    if($i == 1) $time = $time1;
    if($i == 2) $time = $time2;
    if($i == 3) $time = $time3;

    echo('<td>');
    if(min($time1, $time2, $time3) === $time) printf('<b>%.4f</b>', $time);
    else printf('%.4f', $time);
    echo('</td>');
}


$test_cases = array( 123, 12.3, '123', true);
$tests = 1000000;
$result = true;  // Used just to make sure cycles won't get optimized out
echo('<table>'.PHP_EOL);
echo('<tr><td>&nbsp;</td><th>is_int</th><th>ctype_digit</th><th>is_numeric</th></tr>');
foreach($test_cases as $case) {
    echo('<tr><th>'.gettype($case).'</th>');

    $time = microtime(true);
    for($i = 0; $i < $tests; $i++) {
        $result |= is_int((int)rand());
    }
    $time1 = microtime(true)-$time;

    $time = microtime(true);
    for($i = 0; $i < $tests; $i++) {
        $result |= ctype_digit((int)rand());
    }
    $time2 = microtime(true)-$time;

    $time = microtime(true);
    for($i = 0; $i < $tests; $i++) {
        $result |= is_numeric((int)rand());
    }
    $time3 = microtime(true)-$time;

    wr($time1, $time2, $time3, 1);
    wr($time1, $time2, $time3, 2);
    wr($time1, $time2, $time3, 3);
    echo('</tr>'.PHP_EOL);
}

echo('</table>');

exit();