Bug #66166 [Opn->Nab]: in_array() 返回的判断结果是错误的

Edit report at https://bugs.php.net/bug.php?id=66166&edit=1 ID: 66166 Updated by: bwoebi@php.net Reported by: 290315384 at qq dot com Summary: in_array() 返回的判断结果是错误的 -Status: Open +Status: Not a bug Type: Bug Package: *General Issues Operating System: win7 PHP Version: master-Git-2013-11-25 (Git) Block user comment: N Private report: N New Comment: Floating point values have a limited precision. Hence a value might not have the same string representation after any processing. That also includes writing a floating point value in your script and directly printing it without any mathematical operations. If you would like to know more about "floats" and what IEEE 754 is, read this: http://www.floating-point-gui.de/ Thank you for your interest in PHP. Numeric strings are, if the third parameter ($strict) is not set, compared numerically. Too big integers are already casted to float before they are passed to the function in_array. But due to floating point imprecision, it has the same binary representation, so it's true even with strict parameter. Previous Comments: ------------------------------------------------------------------------ [2013-11-25 11:52:13] 290315384 at qq dot com Description: ------------ --- From manual page: http://www.php.net/function.in-array --- PHP version:5.3.13 Package affected: Test script: --------------- <?php $arr = array ('22727824922116425'); var_dump(in_array('22727824922116421',$arr)); //true var_dump(in_array('22727824922116422',$arr)); //true //...... var_dump(in_array('22727824922116426',$arr)); //true var_dump(in_array('22727824922116427',$arr)); //true var_dump(in_array('22727824922116422',$arr,true)); //false $arr = array (22727824922116425); var_dump(in_array(22727824922116422,$arr)); //true var_dump(in_array(22727824922116422,$arr,true));//true ?> ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=66166&edit=1