$decimal = 10; $binary = decbin($decimal); echo $binary; // 输出:1010 $decimal = 10; $binary = decbin($decimal); $binary = str_pad($binary, 8, '0', STR_PAD_LEFT); echo $binary; // 输出:00001010 $decimal = 10; $binary = decbin($decimal); $binary = str_pad($binary, 8, '0', STR_PAD_LEFT); $part = substr($binary, 2, 4); echo $part; // 输出:0010 $decimal = 10; $binary = decbin($decimal); $binary = str_pad($binary, 8, '0', STR_PAD_LEFT); $replaced = str_replace('0', '1', $binary); echo $replaced; // 输出:11111010 这些技巧可以帮助您在处理二进制字符串时更加灵活和高效。